1) Neural basis of bimanual coordination
AK Pimentel-Farfán (email@example.com), BM Soria-Ávila, PE Rueda-Orozco (UNAM)
Many of our dairy movements are bimanual, typing on a keyboard, tying the shoelace or using the cutlery; their accuracy execution requires spatial and temporal coordination. Broad bilateral projections from sensorimotor cortex (M1/S1) to the striatum, make this structure an excellent candidate to integrate sensory input and motor output and coordinate bilateral movements. To investigate the participation of striatum in bimanual coordination, we designed a task for rodents that allows the accurate quantification of kinematic parameters of coordinated movement. Preliminary results indicate that rats develop a coordinate movement naturally, with training the movement of the forelimbs become highly spatially and temporarily correlated. Unilaterally lesion in the striatum causes slowness of the contralateral paw and consequently spatial and temporal uncoupling. Further analysis will clarify is the striatum is required for executing a coordinate motor output or if it will only provide kinematic control.
2) An automated water task to test visual discrimination capacity in freely moving mice
Carlos Sahagún (firstname.lastname@example.org), Esteban Fregoso, Braniff De la Torre-Valdovinos, and Mario Treviño (Universidad de Guadelajara)
The mouse has become a powerful animal model in behavioral neuroscience research. It shares a high percentage of its genome with the human genome and displays a variety of behaviors with relevance to human disease. In our laboratory, we study the circuit mechanisms involved in mouse visual processing. They can be explored electrophysiologically but also with a wide variety of behavioral tests that range from sensory function to more complex behavior related to ‘cognition’ and ’emotionality’. Here, we present a fully automated visual discrimination task that allows visual discrimination learning and rapid testing in adult mice. In principle, this tool will allow us to make an assessment of the visual capacities of many mice. We aim to combine it with pharmacological manipulations to explore whether and how different circuits are involved in the procedural and visual components of the task.
3) Affective predictors of spatial and mathematical performance: A longitudinal study of domain-specific anxieties in elementary-school children
Jillian E. Lauer (email@example.com), Alena G. Esposito, & Patricia J. Bauer (Emory University)
In adulthood, domain-specific anxieties negatively relate to performance on measures of spatial and mathematical aptitude. However, few studies have examined the development of these domain-specific anxieties or their effects on cognition during childhood. We conducted a longitudinal study of 520 elementary-school children aged 6 to 12 years to assess the developmental trajectory of math and spatial anxiety and the anxiety-performance relation within both domains. We found that individual differences in children’s self-reported math and spatial anxiety exhibited moderate stability over two time points, 12 months apart. Moreover, a negative relation between math anxiety and math achievement emerged during the elementary-school years and increased with age, suggesting that relevant academic experiences may be critical to the development of this association. Conversely, spatial anxiety was not found to predict spatial performance during elementary school, calling into question whether the negative effects of spatial anxiety found in adulthood are present earlier in development.
4) Zebra finches learn vocal sequences within a rhythmic framework
Julia Hyland Bruno (firstname.lastname@example.org) & Ofer Tchernichovski (Hunter College)
Birdsong is composed of complex sequences of song syllables. Chains of neuronal activity in the premotor nucleus HVC generate each syllable, and vocal sequences are thought to be composed by further chaining syllables into song phrases. However, here we present evidence from controlled song learning experiments that song sequences are organized rhythmically. We trained juvenile zebra finches to change their songs by incorporating a new syllable which either fit or deviated slightly from the prior rhythm. This deviation had striking effects on the learning outcome: first, birds were less likely to fully accomplish the learning task. Second, tracking song development shows that new syllables were often incorporated by reusing a pre-existing rhythmic slot. Findings suggest that the song system is primarily a rhythm generator, and that vocal sequences are learned within a content-independent framework, which is also learned.
5) The role of dopamine in sensorimotor adaptation
Varun Saravanan (email@example.com) , Lukas A Hoffmann, Samuel J Sober (Emory University)
Dopamine is a neurotransmitter in the brain thought to be important for reinforcement learning, a subset of a broader category of sensorimotor learning. Dopamine’s role in sensorimotor learning as a whole is not well understood. We use two sensorimotor learning paradigms in songbirds (Bengalese finches, Lonchura striata var. domestica), one based on reinforcement learning to an aversive auditory cue and the other based on the bird’s evaluation of its (experimentally manipulated) sensory feedback. We have previously shown that dopamine is necessary for reinforcement type vocal learning (Hoffmann et al 2016). We used a combination of a dopamine depletion paradigm specific to the song learning basal ganglia nucleus and a pair of custom-built headphones designed to manipulate auditory feedback the bird receives to study the role of dopamine in sensorimotor adaptation. Preliminary results suggest that dopamine may be involved in active maintenance of the desired pitch of birdsong in sensorimotor adaptation.
6) Sleep deprivation differentially affects learning and place cell stability in aged and young adult mice
Robin K. Yuan (firstname.lastname@example.org, University of Pennsylvania) and Isabel A. Muzzio (University of Texas at San Antonio)
We examined the effects of acute, post-learning sleep deprivation (SD) on place cell activity in aged and young adult mice performing an object-place recognition task. We found that SD impaired memory performance in young mice but enhanced it in aged animals. The enhanced learning observed in old SD animals correlated with increased consolidation of NREM sleep during subsequent recovery sleep, as well as a distinct cellular phenotype that resembled those of young controls. Specifically, successful performance of the task required animals to maintain a stable representation of the context while updating representations of object locations, cellular processes that were differentially affected in behaviorally impaired old controls and young SD mice. These data indicate that the increase in sleep fragmentation observed in aged animals may account for some of the cognitive deficits associated with aging. Furthermore, acute SD may serve to restore normal sleep patterns and improve memory.
7) When Opportunity Knocks: Probed Self-Generation Leads to Robust Recall of Target Information
Jessica A. Dugan (email@example.com) & Patricia J. Bauer (Emory University)
Building a knowledge base is a primary task of childhood – one done through several means including direction instruction, active learning exercises, reading, and critically, productive extension. Self-derivation is a form of productive knowledge extension in which separate but related episodes of new learning are integrated to derive new factual knowledge. Little is known about the robustness of self-derived knowledge relative to explicitly-taught information. To test whether robust memory for self-derived knowledge depends on the mere opportunity to integrate or from the actual realization of the integration, eight-year-olds read pairs of stories containing varying opportunities to integrate across episodes. Results show that knowledge base development benefits from opportunities to learn through integration of separate yet related facts. Knowledge derived in this manner is as robust as information that is explicitly taught. Importantly, robust performance depends on actualization of the latent potential to derive new knowledge.
8) Ventral striatum is necessary for the appetitive, but not aversive, component of a learned motivational conflict task
Elizabeth Illescas-Huerta (firstname.lastname@example.org), Leticia Ramírez-Lugo, and Francisco Sotres-Bayón (UNAM)
Learning to approach appetitive and avoid aversive environmental stimuli is critical for survival. Although the brain structures that acquire predictive motivational value for appetitive and aversive stimuli have been investigated, it is not clear how these components interact when individuals are faced with both motivations presented simultaneously. We developed a motivational conflict task where rats are trained to approach an appetitive stimulus despite the presence of an aversive stimulus. We evaluated the distinct components of the task (appetitive, aversive and conflict) using: (i) systemic injection of a benzodiazepine drug (diazepam) or (ii) local inactivation of the ventral striatum (VS). We found that diazepam impairs the motivational conflict, but not other component of the task. In contrast, the inactivation of VS impaired the appetitive while leaving intact the aversive and conflict component. Further experiments are underway to investigate the contribution of other brain structures in the components of the motivational conflict.
9) Neonatal perirhinal cortex lesions impair monkeys’ ability to modulate their emotional responses
Nathan Ahlgrim (email@example.com), Jessica Raper, Emily Johnson, Jocelyne Bachevalier (Emory University)
The perirhinal cortex is involved in object recognition and certain emotional responses. Rhesus monkeys with neonatal lesions to the perirhinal cortex (Neo-PRh) were tested on the Human Intruder (HI) task across development to assess the role of the PRh in the development of emotional behaviors. The HI task presents a tiered social threat, to which typically developing animals modulate their emotional responses. Unlike animals with neonatal amygdala or hippocampal lesions, Neo-PRh animals were not broadly hyper- or hypo-responsive to the HI task. Neo-PRh lesions impaired animals’ ability to appropriately modulate freezing and anxiety-like behaviors. Impaired transmission of visual stimuli to limbic structures may explain the inability to appropriately assess and react to complex social stimuli. Basal and reactive cortisol levels were not affected. These results suggest that the PRh is indirectly involved in the expression of emotional behavior, its role being dissociable from the amygdala and hippocampus.
10) Activation of the NMDAr enhance the aversive gustatory memory formation
Olvera-Caltzontzin (firstname.lastname@example.org), MI. Miranda (UNAM)
Memory formation is study with Conditioned Taste Aversion (CTA), in which a novel taste is paired with a gastric malaise produced by and LiCl injection, causing a decrease in the consumption of this new taste. Latent inhibition (LI) of the CTA study familiarity, is when the taste is pre-expose without the gastric malaise, decreasing the association with the aversive stimuli when presented. The blockage of the NMDAr in the insular cortex impairs the acquisition of CTA but not the LI-CTA. Some rats were pre-exposed to a sweet solution for 10 min. During the acquisition session rats with or without sugar pre-exposition received an intracortical injection of NMDA in the IC, after the sugar presentation and before the LiCl. Liquid intake was measure during retrieval and extinction. These results demonstrate that the NMDAr has active role in the memory formation of both the CTA and the LI of CTA.
11) Medial axis structure supports three-dimensional object recognition
Vladislav Ayzenberg (email@example.com) & Stella F. Lourenco (Emory University)
To identify an object the visual system must rapidly relate and compare a visible object to the representation stored in memory. The computational challenge for the visual system is that the appearance of objects varies greatly across viewpoints and exemplars. Yet, humans are able to, both, identify the same object across large viewpoint changes, and extend category membership to novel exemplars. Here we propose that a model of object structure based on the medial axis is able to account for many object recognition abilities. We find that the medial axis, independent of image similarity, is predictive of human perceptual similarity judgments for novel 3-D objects (Experiment 1). Critically, we find that participants accurately categorize objects on the basis of their medial axes even across large image-level changes (Experiment 2). Together these findings emphasize the role of object structure as a core mechanism for determining object identity.
12) Rhesus monkeys (Macaca mulatta) show evidence of working memory rehearsal for unfamiliar stimuli in the match to sample paradigm
Ryan J.Brady (firstname.lastname@example.org) & Robert R. Hampton (Emory University)
In humans, working memory rehearsal relies heavily on access to linguistic representations. The absence of language draws into question the extent to which nonhumans possess similar mechanisms of working memory rehearsal. Previous research in monkeys has found evidence of working memory rehearsal when testing monkeys with highly familiar stimuli, but not with unfamiliar stimuli. One explanation may be that in tests of recognition memory, evidence of working memory rehearsal is not found with unfamiliar stimuli because monkeys choose the sample based on relative familiarity, rather than working memory. In the current study, we attenuated the use of familiarity in a novel MTS paradigm and observed the effects of concurrent cognitive load on memory performance. Our results indicated that a concurrent cognitive load did decrease memory performance for unfamiliar stimuli, but only when familiarity was attenuated. These results provide evidence of active working memory rehearsal for unfamiliar visual stimuli.
13) Dissociating intuitive physics from intuitive psychology: Evidence from Williams syndrome
Frederik S. Kamps(email@example.com), Joshua B. Julian, Peter Battaglia, Barbara Landau, Nancy Kanwisher, & Daniel D. Dilks (Emory University)
Prior work suggests that our understanding of how things work (“intuitive physics”) and how people work (“intuitive psychology”) are distinct domains of human cognition. Here we directly test the dissociability of these two domains by investigating knowledge of intuitive physics and intuitive psychology in adults with Williams syndrome (WS) – a genetic developmental disorder characterized by severely impaired spatial cognition, but relatively spared social cognition. WS adults and mental-age matched (MA) controls completed an intuitive physics task and an intuitive psychology task. If intuitive physics is a distinct domain (from intuitive psychology), then we should observe differential impairment on the physics task for individuals with WS compared to MA controls. Indeed, adults with WS performed significantly worse on the intuitive physics than the intuitive psychology task, relative to controls. These results support the hypothesis that knowledge of the physical world can be disrupted independently from knowledge of the social world.
14) Numerical Abilities of Children with Down Syndrome: Evidence from Looking Time and Neuropsychological Studies
Roberto A. Abreu-Mendoza (firstname.lastname@example.org, Universidad de Guadelajara) & Natalia Arias-Trejo (UNAM)
Children with Down syndrome (DS) have difficulty learning numerical abilities. In a series of studies, we explored the possibility of a deficit in the ability to compare quantities, a difficulty in understanding the how-to-count principles, and the consequences of affected linguistic abilities as explanations of this phenomenon. In Study 1, we evaluated the abilities of children with DS to compare area and number; in Study 2, we investigated whether children with DS who have not started to produce number words understand the first how-to-count principle that typically developing children acquire (1-to-1 correspondence principle); in Study 3, we looked at the relationship between number word knowledge and receptive vocabulary. Results suggest that the difficulty in learning numerical abilities of children with DS might not be due to affected quantity comparison abilities or a lack of understanding of the 1-to-1 correspondence principle, but might instead be related to vocabulary development.
15) Distinctiveness and the Attentional Boost Effect
Adam Smith (email@example.com) and Neil W. Mulligan (University of North Carolina at Chapel Hill)
The typical pattern of results in divided attention experiments is that subjects in a full attention (FA) condition perform markedly better on tests of memory than subjects in a divided attention (DA) condition which forces subjects to split their attention between studying to-be-remembered stimuli and completing some peripheral task. Nevertheless, recent research has revealed an exception wherein stimuli presented concurrently with targets in a detection task are better remembered than stimuli which co-occur with distractors. Research on this phenomenon – the Attentional Boost Effect (ABE) – has demonstrated that the ABE is reduced or eliminated for words made distinct by their word frequency or orthographic properties – forms of secondary distinctiveness. However, it is unclear how primary distinctiveness effects may interact with the ABE. The current study observed how perceptual and semantic manipulations of primary distinctiveness interact with the ABE, and revealed these interactions to be fundamentally different than those of secondary distinctiveness.
16) Automated memory testing of winter flocks of birds in semi-natural conditions
Emily Kathryn Brown (firstname.lastname@example.org, Emory University), David F. Sherry (Western University), & Robert R. Hampton (Emory University)
Because cognitive processes are shaped by long- and short-term environmental pressures, cognition is best understood in its natural context. Laboratory experiments allow meticulous control of variables, but remove cognition from this context. Here we describe an automated cognitive testing system for wild birds that allows precise measurements of cognition in natural contexts.
We housed groups of wild-caught birds in outdoor aviaries that approximated natural conditions, including light cycles, weather, and social interactions. Individuals were fitted with rfID tags for automated identification. We trained birds to interact with the testing equipment, which rewarded responses with rich, preferred food. Birds completed trials despite ad libitum availability of other food. Here we describe training and acquisition of a delayed match-to-sample memory task. Our preliminary data illustrate the potential of our testing system for comparative cognition research.
17) Analysis of the cerebral connectivity that underlies the audio-motor integration induced by sounds with temporal structure
Penélope Martínez Campos (email@example.com), Luis Concha Loyola (UNAM)
Music engages distributed set of cortical modules that process different perceptual, cognitive and emotional components with varying selectivity (Warren, J., 2008). Angulo-Perkins, et al. (2014) through fMRI, found that the planum polare (located in the anterior portion of the superior temporal gyrus) presents a greater activity listening to music, suggesting that this structure is a relay in the stream of musical stimuli, which receives information from the central regions and which integrates complex acoustic attributes. Wilke et al. (2015) found that the analysis of rhythmic structures requires the activity of the somato-motor regions, which are related to the motor theory of the rhythmic perception. The present research investigates functional connectivity that underlies the audio-motor network integration during resting state, and during listening to manipulated (rhythm, melody and harmony) and continuous music whose complexity increases over time, between listeners with and without professional musical training, using functional magnetic resonance imaging (fMRI).
18) The relationship between white matter integrity and cognitive performance in temporal lobe epilepsy
Rodríguez-Cruces Raúl (firstname.lastname@example.org), Camacho Vicente, Concha Luis (UNAM)
Cognitive functions, like all high-order cerebral functions, rely on the orchestrated activity of multiple cortical and subcortical regions, interconnected by white matter. If the white matter integrity is compromised like in epilepsy, proper cognitive performance could be impaired. Temporal Lobe epilepsy (TLE) is a neurological condition characterized by recurrent seizures whose onset is within the temporal lobe structures. Despite its localized origin TLE presents different patterns of generalized cognitive impairment and white matter abnormalities beyond the affected lobe. Moreover, TLE can have a hippocampal alteration, which is evident with magnetic resonance imaging (MRI) known as mesial temporal sclerosis (MTS). The presence of MTS is associated with larger structural changes and abnormalities in neuropsychometrical tests. We evaluated if the presence of MTS in TLE produces different patterns in the relationship between cognitive performance and white matter integrity. And, finally we describe the structural foundations of cognitive profiles in our sample.
19) Auditory and premotor cortex connectivity in the Macaque monkey
De León C. (email@example.com), García P., Rojas P., Concha L. and Merchant H. (UNAM)
Sensorimotor synchronization (SMS) is the coordination of rhythmic movements with an external rhythm. This SMS ability is esential for a number of human behaviors such as language comprehension, dance and music performance, activities that depend on a dynamic interaction between the auditory and motor system. Neuroimaging and electrophysiological studies have shown that the motor cortico-basal ganglia-thalamocortical circuit (mCBGT), which includes SMA, pre-SMA and the putamen as the fundamental cortical and neostriatal nodes, is involved in perception and motor execution of rhythmic behaviors. Interestingly, it has been demonstrated that neurons in premotor regions (SMA and preSMA) respond to the presentation of auditory stimuli. Thus, the purpose of this study is to elucidate the pathway through which the premotor cortex receives auditory information during audiomotor processing in non-human primates. In a preliminary way, using neuronal tracers we found that neurons in auditory cortex projects directly to the premotor cortex (M2) in rat.
20) Use of Awake fMRI in Dogs to Model Learning of Visual and Olfactory Stimuli
Ashley Prichard (firstname.lastname@example.org), Raveena Chibber, Lana Herrmann, Hope Housman, Mark Spivak & Greg Berns (Emory University)
Through awake fMRI, we examined individual and group learning curves in dogs to previously neutral visual and olfactory stimuli. Visual stimuli were a toy pineapple and inflatable flamingo, and olfactory stimuli were Isoamyl acetate and Hexanol. During scanning, one stimulus of each pair was associated with food reward and the other with nothing. To generate learning curves for individual dogs, we examined activation within the caudate nucleus per trial following the presentation of each stimulus. The learning curves show that dogs did form stimulus-reward associations within a single MRI scan. Our results demonstrate the speed at which conditioning to stimuli associated with reward occurs in the dog brain, and the potential differences between modalities in learning acquisition.
21) Temporal perceptual learning leads to motor timing improvement and BOLD changes in the cortical-basal ganglia circuit
Sánchez-Moncada I. (email@example.com), Concha L., Merchant H. (UNAM)
We measured changes in BOLD signal during a synchronization-continuation task (SCT) after subjects underwent seven days of training in a visual interval-discrimination task (IDT). Behavioral results showed that IDT training reduced subject’s discrimination threshold, which was accompanied by a reduction of their tapping variability during the continuation phase of the SCT. We contrasted the BOLD signal during the SCT before and after the IDT. Increased activity areas include: V1 to V4, L-Inferior parietal lobule, R-caudate, R-thalamus, R-hippocampus, R-Brainstem and CrusI. Additionally we calculated 3 behavioral scores: Learning Slope, Threshold Change and Variability Change. These behavioral scores were correlated, across subjects, with the difference in Pre-Post BOLD signal. In conclusion, we found a time learning transfer of the IDT to the temporal performance of the continuation phase. This generalization was associated with an increase in BOLD signal in visual areas, the IPS, the cortical-basal ganglia circuit and the cerebellum after training.
22) Psychotherapists show significant differences in perspective taking, emotional regulation and brain functional connectivity
Victor Olalde-Mathieu (firstname.lastname@example.org, UNAM), Roberto Mercadillo (UAM), Federica Sassi (UNAM), Erick Pasaye (UNAM), Fernando Barrios (UNAM), Sarael Alcauter (UNAM)
Little is known about the neural substrate of the different components of the empathic response and how they can be modulated with training. To get more understanding of these interactions we characterized a group of alliance-therapists which long-term training (>2 years) is based in the frequent modulation of such empathic components, including perspective taking and emotional regulation. We contrasted behavioral scores and fMRI resting state functional connectivity (FC) of a series of regions involved with perspective taking and emotion regulation, in a group of therapists and non-therapists. The therapists showed significantly higher scores in perspective taking, and significantly lower scores in emotional suppression. In addition, therapists showed less FC between PCC and Precuneus, which are involved with inference process and autobiographical retrieving. In sum, these results suggest that the modulation of the empathic response is different in the therapists, and that these differences can be reflected in their FC.
23) Relationship between working memory, IQ, and temporal processing during different synchronization-continuation tasks in healthy human subjects.
García-Saldivar P. (email@example.com), De León-Andrez C., Merchant, H. (UNAM)
Temporal performance during rhythmic tapping to an auditory metronome is more accurate and precise than tapping to a visual metronome, however, there are few studies relating tapping performance to a metronome with the subjects’ cognitive abilities. The purpose of this study is to evaluate the timing performance during a synchronization-continuation tapping task (SCT) where subjects will tap in synchrony to a sensory metronome with a different modality (auditory or visual) and condition of stimulus (static or dynamic) and to correlate the temporal performance with the cognitive skills. Twenty healthy human subjects (twenty to thirty-year-old) were assessment through neuropsychological tests. Furthermore, the subjects were performed the SCT with the four different metronome conditions. The preliminary results support the notion that visual timing improves when a moving visual stimulus is used to drive tapping performance, and that there is a relation between the cognitive skills and the timing abilities during rhythmic synchronization.
24) Dynamic functional connectivity of overt and covert autobiographical memory retrieval
Charles Ferris (firstname.lastname@example.org), Cory Inman, G.Andrew James, & Stephan Hamann (Emory University)
Retrieval of autobiographical memories (AM) is a complex process that recruits a core network of brain regions. In prior fMRI work we have used graph analyses to characterize whole-brain changes in connectivity during AM retrieval. Here we used high temporal and spatial resolution fMRI, an optimized experimental design, and both covert and overt (spoken) retrieval to test theoretical accounts of dynamic AM retrieval processes. During scanning, healthy adults retrieved unrehearsed AMs to cue words across an extended retrieval period, followed by ratings of vividness and emotion, with overt (spoken) retrieval during half of the runs. We observed functional connectivity patterns in line with those identified in prior work that were largely constant across overt and covert retrieval patterns. Overt retrieval showed selectively greater functional connectivity throughout AM retrieval of the left ventrolateral prefrontal cortex to both the left amygdala and to the left hippocampus.
25) Time categorization in the primate pre-SMA: single neuron correlates for boundaries, categorical decisions and reward outcomes
Mendoza G (email@example.com, UNAM), Méndez JC (University of Oxford), Pérez O (UNAM), Prado L (UNAM), Merchant H (UNAM)
Categorizing intervals as short or long depends on the ability to perceive the passage of time and to assign different stimuli to specific categories, both fundamental primate cognitive skills. To determine the underlying neural mechanism, we recorded the activity of pre-SMA neurons of monkeys executing a categorization task in which the boundary changed between blocks of trials. Single neurons encoded all of the critical features of the task, namely, the subjective boundary between categories, the category selected by the monkeys, and the outcome of the decision. The decoding and a neural network model suggest that monkeys compared the representation of the categorical boundary with the neural representation of time to classify the intervals as short or long. In conclusion, single, probably interacting, pre-SMA neurons encoded the crucial information needed to perceive and categorize intervals, as well as to evaluate the outcome of such perceptual decisions.
26) Oscillatory bursting activity of supplementary motor areas encodes temporal patterns
Cadena-Valencia J (firstname.lastname@example.org)and De Lafuente V (UNAM)
The perception of periodic events is essential to anticipate to imminent changes in the environment. To coordinate a timed response, the motor system must encode temporal regularities. Previous reports show that supplementary motor area (SMA) is important to perform timed movements; however it is not known if this structure is also important to identify temporal regularities besides generating timed motor commands. We trained monkeys in a task in which they attended to a rhythmic visual pattern: a circle that changed position at constant frequency. After three changes, the circle vanished and the monkeys had to predict the position of the circle. While performing the task, local field potentials where recorded in the SMA. When monkeys predict future changes, Gamma band amplitude increments rhythmically according with the observed pattern. This suggests that SMA is important to integrate temporal regularities in the environment even in the absence of a motor command.
27) Moderate Exercise Combined with Low-Dose Lithium Treatment Prevents the Amyloid β-Induced Hippocampal Network Disruption
Arturo G. Isla (email@example.com) and Fernando Peña-Ortega (UNAM)
Amyloid β is responsible for the early impairment of learning and memory related to neuronal network dysfunction. Particularly, with the beginning and maintenance of hippocampal theta rhythm that is essential for memory process. Recent evidence shows that lithium, that has been used as a treatment for bipolar disorder, prevents the effect produced by Aβ, promoting the use of lithium as AD treatment in clinical trials. Nevertheless, lithium produces multiple side effects that limits their therapeutic use. Additionally, we and others are exploring other strategies for preventing Aβ-induced disruption of hippocampal activity. One of those is exercise, despite that the exercise generates a protective effect on clinical trials become challenging during aging. The aim of this project is to find if a low dose of lithium, combined with a short regime of exercise that have a cumulative effect of both treatments by itself against Aβ-induced inhibition of hippocampal activity.
28) Secondary Auditory Cortical Responses Shift Towards Statistically Likely Acoustic Features in a Learned Vocal Category
Kelly K. Chong (firstname.lastname@example.org, Georgia Tech and Emory University), Kathryn N. Shepard (Emory University), and Robert C. Liu (Emory University)
Natural sounds, including communication sounds, often have inherent acoustic variability within a sound category. In the mouse, pup ultrasonic vocalizations (USVs) represent an acoustic category that is easily parameterized and can be learned as behaviorally relevant by maternal mice. Pup calls show inherently high variability in frequency and duration, and relatively less variability in onset frequency modulation. We hypothesized that the likelihood of acoustic variability along a specific acoustic dimension shapes experience-dependent auditory cortical plasticity. Specifically, auditory cortex becomes more responsive along a dimension with inherently high variability (frequency and duration), and less responsive along a dimension with inherently low variability (onset frequency modulation). Using electrophysiological methods, our data suggest that in a natural social communication learning context, noncore auditory cortical fields are shaped by experience in a way that better attunes neural responses to the statistics of behaviorally relevant vocalizations.
29) Subclinical doses of ATP-sensitive potassium channel modulators prevent alterations in memory and synaptic plasticity induced by Amyloid β
Karla Salgado-Puga (email@example.com), Javier Rodríguez-Colorado, Roberto A. Prado-Alcalá and Fernando Peña-Ortega (UNAM)
ATP-sensitive potassium channels (KATP) couple cell metabolism and excitability, and are involved in neural function and plasticity. Interestingly, in Alzheimer’s Disease (AD) and Amyloid-β (Aβ)-induced pathology, there are alterations in KATP activity and expression. Thus, KATP modulation could influence Aβ-induced alterations on memory and hippocampal function. Subclinical doses treatment with a KATP blocker (Tolbutamide) or a KATP opener (Diazoxide) differentially restrained Aβ-induced memory deficit and synaptic plasticity imbalance (LTP inhibition and LTD promotion). The protective effect of Tolbutamide against Aβ-induced memory deficit, strongly correlated with synaptic plasticity balance reestablishment. In contrast, the mild protection against Aβ-induced memory deficit produced by Diazoxide was not. Interestingly, treatment with both KATP modulators prevented the hippocampal network activity inhibition induced by Aβ. These findings indicate that KATP are involved in Aβ-induced pathology and emphasize the potential role of KATP as a therapeutic target in AD.
30) Precise spike-timing codes for motor control
Andrea Pack (firstname.lastname@example.org, Emory University), Kyle Srivastava (Emory University), Caroline Holmes(Emory University), Michiel Vellema(University of Southern Denmark), Coen Elemans(University of Southern Denmark), Ilya Nemenman(Emory University), and Sam Sober(Emory University)
Past research revealed that millisecond-scale spike timing differences in songbird motor cortex predict variation in vocal behavior, but it is still unknown whether or how the neural spike timing-based coding commands translate to patterns of coordinated activity across muscles to perform the behavior. Recently, our lab demonstrated that expiratory muscle stimulation using millisecond-scale spike timing differences caused significant modulation in air sac pressure of an anesthetized songbird. The goal of this study was to determine whether electrical stimulation to the expiratory muscle directly activated motor axons or individual muscle cells. Results indicated that stimulation to the expiratory muscle recruited motor units instead of muscle fibers. Additionally, we established millisecond time scales control expiratory motor unit activity and variations in spike timing patterns significantly alter muscle force output. These results are important for understanding to what extent single-unit action potentials in muscle tissue use a timing based code to control behavior.
31) Estrogen’s effect on acute maternal response behavior and plasticity associated gene expression
Amielle Moreno (email@example.com, Emory University), Matt Tucker (Emory University), Parker Lunsford(The Paideia School) & Robert Liu (Emory University)
Recent research suggests long-term changes in a mother’s auditory cortex lead to enhanced recognition and response to infant vocalizations. However, it is currently unknown what immediate molecular mechanisms are enacted during infant experience to lead to this enhanced neural response. The parturition hormone estrogen is associated with maternal behavior as well as learning and memory through the expression of the plasticity related gene, brain derived neurotrophic factor (bdnf). Here, we use a mouse maternal model to investigate the effect of the social neuromodulator estrogen on both behavior and the transcription of bdnf at the site of cortical auditory processing in response to acute pup-caring experience. By examining changes in bdnf expression and behavior, we investigate the molecular underpinnings associated with the early stages of auditory cortex plasticity which might be responsible for enhancing future infant stimuli processing.
NEURAL NETWORKS AND BIG DATA
32) Insights into narrative coherence and wellbeing using neural networks
Matthew E. Graci (firstname.lastname@example.org), Robert Thorstad, Theo Waters, Robyn Fivush, & Phillip Wolff (Emory University)
Although broadly assumed, there is surprisingly little research on relations between narrative coherence of personal memories and wellbeing. Narrative coherence is a complex construct, including structural and semantic components, thus requiring multiple levels of analysis, along with investigating linear and curvilinear relations to wellbeing. Curvilinear relations, in particular, may indicate disorganization and rigidity as the lower and upper ends of coherence. We compared hand-coded measures of structural coherence to newly developed semantic coherence, captured by vector-symbolic-representations using neural networks. Semantic coherence is curvilinearly related with structural coherence, and wellbeing, suggesting there is an optimal level of semantic coherence relating to structural coherence and wellbeing.
33) Temporal Horizons and Decision-Making: A Big Data Approach
Robert Thorstad (email@example.com) & Phillip Wolff (Emory University)
Human behavior is plagued by shortsightedness. When faced with two options, smaller rewards are often chosen over larger rewards, even when such choices are potentially costly. In three experiments, we use big data techniques to examine how such choices might be driven by people’s temporal horizons. In Experiment 1, we determine the average distance into the future people talk about in their tweets in order to determine the temporal horizon of each U.S. state. States with further future horizons had lower rates of risk taking. In Experiment 2, we used an individual’s tweets to establish their temporal horizon and found that those with longer temporal horizons were more willing to wait for larger rewards. In Experiment 3, we show with tweets that those with longer future horizons were less likely to take risks. The findings help establish a relationship between future thinking and decision-making.