Two distinct representations of social vocalizations in the basolateral amygdala.
*Discrimination (Psychology); *Social Behavior; *Vocalization; acoustic communication; Action Potentials; Amygdala/cytology/*physiology; Animal; Animals; bat; Chiroptera; electrocardiogram; Eptesicus fuscus; Female; Heart Rate; Male; Neurons/classification/*physiology; vocalizations
Acoustic communication signals carry information related to the types of social interactions by means of their "acoustic context," the sequencing and temporal emission pattern of vocalizations. Here we describe responses to natural vocal sequences in adult big brown bats (Eptesicus fuscus). We first assessed how vocal sequences modify the internal affective state of a listener (via heart rate). The heart rate of listening bats was differentially modulated by vocal sequences, showing significantly greater elevation in response to moderately aggressive sequences than appeasement or neutral sequences. Next, we characterized single-neuron responses in the basolateral amygdala (BLA) of awake, restrained bats to isolated syllables and vocal sequences. Two populations of neurons distinguished by background firing rates also differed in acoustic stimulus selectivity. Low-background neurons (\textless1 spike/s) were highly selective, responding on average to one tested stimulus. These may participate in a sparse code of vocal stimuli, in which each neuron responds to one or a few stimuli and the population responds to the range of vocalizations across behavioral contexts. Neurons with higher background rates (\textgreater/=1 spike/s) responded broadly to tested stimuli and better represented the timing of syllables within sequences. We found that spike timing information improved the ability of these neurons to discriminate among vocal sequences and among the behavioral contexts associated with sequences compared with a rate code alone. These findings demonstrate that the BLA contains multiple robust representations of vocal stimuli that can provide the basis for emotional/physiological responses to these stimuli.
Gadziola Marie A; Shanbhag Sharad J; Wenstrup Jeffrey J
Journal of neurophysiology
2016
2016-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/jn.00953.2015" target="_blank" rel="noreferrer noopener">10.1152/jn.00953.2015</a>
Projections to the inferior colliculus from layer VI cells of auditory cortex.
Amidines/metabolism; Animals; Auditory Cortex/*cytology/*physiology; Cholera Toxin/metabolism; Efferent Pathways/physiology; Fluorescent Dyes/metabolism; Functional Laterality; Guinea Pigs; Inferior Colliculi/*physiology; NADPH Dehydrogenase/metabolism; Neurons/classification/*physiology; Nitric Oxide Synthase Type I/metabolism
A large injection of a retrograde tracer into the inferior colliculus of guinea pigs labeled two bands of cells in the ipsilateral auditory cortex: a dense band of cells in layer V and a second band of cells in layer VI. On the contralateral side, labeled cells were restricted to layer V. The ipsilateral layer VI cells were distributed throughout temporal cortex, suggesting projections from multiple auditory areas. The layer VI cells included pyramidal cells as well as several varieties of non-pyramidal cells. Small tracer injections restricted to the dorsal cortex or external cortex of the inferior colliculus consistently labeled cells in layer VI. Injections restricted to the central nucleus of the inferior colliculus labeled layer VI cells only rarely. Overall, 10% of the cells in temporal cortex that project to the ipsilateral inferior colliculus were located in layer VI, suggesting that layer VI cells make a significant contribution to the corticocollicular pathway.
Schofield B R
Neuroscience
2009
2009-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.neuroscience.2008.11.013" target="_blank" rel="noreferrer noopener">10.1016/j.neuroscience.2008.11.013</a>
Activation and circuitry of uterine-cervix-related neurons in the lumbosacral dorsal root ganglia and spinal cord at parturition.
Analysis of Variance; Animals; Blotting; Cell Count/methods; Cervix Uteri/*cytology; Cyclic AMP Response Element-Binding Protein/metabolism; Estrogen Receptor alpha/metabolism; Female; Ganglia; Gene Expression Regulation/physiology; Immunohistochemistry/methods; Lumbosacral Region; Models; Nerve Net/cytology/*physiology; Neurological; Neurons/classification/*physiology; Oncogene Proteins v-fos/metabolism; Parturition/*physiology; Pregnancy; Rats; Spinal Cord/*cytology; Spinal/*cytology; Sprague-Dawley; Stilbamidines/metabolism; Time Factors; Western/methods
Stimulation of the uterine cervix at parturition activates neural circuits involving primary sensory nerves and supraspinally projecting neurons of the lumbosacral spinal cord, resulting in output of hypothalamic neurohormones. Dorsal root ganglia (DRG) and spinal neurons of these circuits are not well-characterized. The objectives of this study were to detail the activation of DRG and spinal neurons of the L6/S1 levels that are stimulated at late pregnancy, verify hypothalamic projections of activated spinal neurons, and determine whether activated neurons express estrogen receptor-alpha (ERalpha). Expression of phosphorylated cyclic-AMP response element-binding protein (PCREB) and Fos immunohistochemistry were used to "mark" activated DRG and spinal neurons, respectively. Retrograde tracing identified uterine-cervix-related and spinohypothalamic neurons. Baseline PCREB expression in the DRG increased during pregnancy and peaked during the last trimester. Some PCREB-expressing neurons contained retrograde tracer identifying them as cervix-related neurons. Fos-expressing neurons were few in spinal cords of nonpregnant and day 22 pregnant rats but were numerous in parturient animals. Some Fos-expressing neurons located in the dorsal half of the spinal cord contained retrograde tracer identifying them as spinohypothalamic neurons. Some DRG neurons expressing PCREB also expressed ERalpha, and some spinal neurons activated at parturition projected axons to the hypothalamus and expressed ERalpha. These results indicate that DRG and spinal cord neurons are activated at parturition; that those in the spinal cord are present in areas involved in autonomic and sensory processing; that some spinal neurons project axons to the hypothalamus, ostensibly part of a neuroendocrine reflex; and that sensory and spinal neurons can respond to estrogens. Moreover, some activated sensory neurons may be involved in the animal's perception of labor pain.
Puder B A; Papka R E
Journal of neuroscience research
2005
2005-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jnr.20690" target="_blank" rel="noreferrer noopener">10.1002/jnr.20690</a>