Response characteristics of amygdaloid neurons provoked by emotionally significant environmental stimuli in cats, with special reference to response durations

1993 ◽  
Vol 71 (5-6) ◽  
pp. 374-378 ◽  
Author(s):  
Hisao Maeda ◽  
Hiroshi Morimoto ◽  
Kazuyuki Yanagimoto
Keyword(s):  
Response Duration ◽  
Stimulus Presentation ◽  
Neuronal Responses ◽  
Environmental Stimuli ◽  
Response Characteristics ◽  
Aversive Stimuli ◽  
Appetitive Stimuli ◽  
Freely Moving ◽  
Adult Cats ◽  
Period Pattern

Extracellular single or multiple neuronal activities were recorded from the basolateral portion of the amygdala of wild adult cats under an unanesthetized, freely moving condition, and neuronal responsiveness to neutral, aversive, and appetitive stimuli was studied. Of 71 units, 47 (66%) responded to some of the stimuli. The patterns of neuronal responses were classified into three types on the basis of response duration. Of the responses sampled, 9% rapidly attenuated and disappeared before termination of stimulus presentation (pattern A), 58% of responses were maintained during the period of the stimulus presentation but disappeared abruptly after termination (pattern B), and 33% of responses markedly outlasted the stimulus presentation period (pattern C). Pattern A responses habituated readily and were most prominent when neutral stimuli were presented, so this type of response was considered to underlie alterting or orienting responses. Pattern B responses were observed equally for the three kinds of stimuli, and were suggested to be predominantly involved in perception of the environmental stimuli. Pattern C responses habituated least and tended to be elicited more frequently by aversive stimuli. This type of response was interpreted to reflect emotional arousal. These findings were considered to be compatible with the hypothesis that the amygdala plays an important role in converting environmental stimuli into emotions such as rage or fear.Key words: emotions, aversiveness, appetitiveness, amygdala, extracellular neuronal activity.

Intermittent stimulus presentation stabilizes neuronal responses in macaque area MT

2012 ◽  
Vol 108 (8) ◽  
pp. 2101-2114 ◽  
Author(s):  
P. Christiaan Klink ◽  
Anna Oleksiak ◽  
Martin J. M. Lankheet ◽  
Richard J. A. van Wezel
Keyword(s):  
Neuronal Response ◽  
Stimulus Presentation ◽  
Sensory Stimulation ◽  
Response Variability ◽  
Spike Timing ◽  
Response Magnitude ◽  
General Effect ◽  
Neuronal Responses ◽  
Area Mt ◽  
Response Characteristics

Repeated stimulation impacts neuronal responses. Here we show how response characteristics of sensory neurons in macaque visual cortex are influenced by the duration of the interruptions during intermittent stimulus presentation. Besides effects on response magnitude consistent with neuronal adaptation, the response variability was also systematically influenced. Spike rate variability in motion-sensitive area MT decreased when interruption durations were systematically increased from 250 to 2,000 ms. Activity fluctuations between subsequent trials and Fano factors over full response sequences were both lower with longer interruptions, while spike timing patterns became more regular. These variability changes partially depended on the response magnitude, but another significant effect that was uncorrelated with adaptation-induced changes in response magnitude was also present. Reduced response variability was furthermore accompanied by changes in spike-field coherence, pointing to the possibility that reduced spiking variability results from interactions in the local cortical network. While neuronal response stabilization may be a general effect of repeated sensory stimulation, we discuss its potential link with the phenomenon of perceptual stabilization of ambiguous stimuli as a result of interrupted presentation.

Response Characteristics of Cochlear Nucleus Neurons to Vowel Sounds

1977 ◽  
Vol 86 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Allen L. Rupert ◽  
Donald M. Caspary ◽  
George Moushegian
Keyword(s):  
Cochlear Nucleus ◽  
Discharge Rate ◽  
Neuronal Responses ◽  
Response Characteristics ◽  
Cochlear Nuclei ◽  
Kangaroo Rat ◽  
Complete Basis ◽  
Pure Tones ◽  
Neural Discharge ◽  
Tonal Stimuli

Most studies in auditory neurophysiology have utilized tonal stimuli to determine the coding properties of neurons in the cochlear nuclei. In this investigation of the kangaroo rat, cochlear nuclei, neuronal responses to vowel sounds, as well as tones, were studied. The vowel sounds, each about 40 msec in duration were: [a], [i], [I], [ε], [o], [u], [Formula: see text] [æ], and [ṛ]. Five were linked together to form a 200 msec stimulus and various combinations of five vowel sounds provided us with 18 different stimuli. The results show that neurons in the cochlear nuclei are remarkably sensitive and selective to vowel sounds. Furthermore, the responses of these neurons to pure tones do not provide a complete basis to predict the types of responses to the vowel sounds. More significant is the finding that the neural discharge rate and pattern of discharge to a particular vowel may depend on where the vowel appears in the stimulus and what other vowel precedes it. This vowel positional effect is not the same for every neuron. We have called this phenomenon a neural “set.”

Coding Strategies in Monkey V1 and Inferior Temporal Cortices

1998 ◽  
Vol 79 (3) ◽  
pp. 1135-1144 ◽  
Author(s):  
Ethan D. Gershon ◽  
Matthew C. Wiener ◽  
Peter E. Latham ◽  
Barry J. Richmond
Keyword(s):  
Channel Capacity ◽  
Gaussian Distribution ◽  
Dynamic Range ◽  
Spike Count ◽  
Neuronal Responses ◽  
Response Characteristics ◽  
Cortical Areas ◽  
Count Response ◽  
Coding Strategies ◽  
The Mean

Gershon, Ethan D., Matthew C. Wiener, Peter E. Latham, and Barry J. Richmond. Coding strategies in monkey V1 and inferior temporal cortices. J. Neurophysiol. 79: 1135–1144, 1998. We would like to know whether the statistics of neuronal responses vary across cortical areas. We examined stimulus-elicited spike count response distributions in V1 and inferior temporal (IT) cortices of awake monkeys. In both areas, the distribution of spike counts for each stimulus was well described by a Gaussian distribution, with the log of the variance in the spike count linearly related to the log of the mean spike count. Two significant differences in response characteristics were found: both the range of spike counts and the slope of the log(variance) versus log(mean) regression were larger in V1 than in IT. However, neurons in the two areas transmitted approximately the same amount of information about the stimuli and had about the same channel capacity (the maximum possible transmitted information given noise in the responses). These results suggest that neurons in V1 use more variable signals over a larger dynamic range than IT neurons, which use less variable signals over a smaller dynamic range. The two coding strategies are approximately as effective in transmitting information.

Response characteristics of neurons in chick forebrain slices

1988 ◽  
Vol 234 (1275) ◽  
pp. 145-157 ◽  
Keyword(s):  
Field Potential ◽  
Neuronal Responses ◽  
Response Characteristics ◽  
Local Responses ◽  
Chick Forebrain ◽  
Intermediate Part ◽  
Unit Action ◽  
Hyperstriatum Ventrale ◽  
Stimulation Of

Coronal sections were taken from the forebrains of domestic chicks, aged 1-20 days, and maintained in vitro . Extracellular recordings of neural activity were made from the intermediate part of the medial hyperstriatum ventrale (IMHV). Spontaneous activity was rarely recorded, but neuronal responses could be evoked by stimulation of various sites. Each recording point was surrounded by an arc of sites which, when stimulated, typically elicited a short-latency field potential. These ‘local responses’ could be recorded in slices from chicks of any age. Stimulation of more distant sites failed to evoke field potentials from the IMHV. Instead, trains of large, unit action potentials appeared on an undisturbed base­-line. Such ‘unit’ responses could only be evoked by stimuli delivered at specific frequencies. They required facilitation, were of variable latency, and often finally decayed. The number of sites capable of evoking a ‘unit’ response from the IMHV fell dramatically in slices taken from chicks older than 4 days.

Neuronal responses to orientation and motion contrast in cat striate cortex

1999 ◽  
Vol 16 (3) ◽  
pp. 587-600 ◽  
Author(s):  
SABINE KASTNER ◽  
HANS-CHRISTOPH NOTHDURFT ◽  
IVAN N. PIGAREV
Keyword(s):  
Striate Cortex ◽  
Coherent Motion ◽  
Neuronal Responses ◽  
Physiological Basis ◽  
Orientation Contrast ◽  
Motion Contrast ◽  
Striate Neurons ◽  
The Mean ◽  
Adult Cats ◽  
Main Effects

Responses of striate neurons to line textures were investigated in anesthetized and paralyzed adult cats. Light bars centered over the excitatory receptive field (RF) were presented with different texture surrounds composed of many similar bars. In two test series, responses of 169 neurons to textures with orientation contrast (surrounding bars orthogonal to the center bar) or motion contrast (surrounding bars moving opposite to the center bar) were compared to the responses to the corresponding uniform texture conditions (all lines parallel, coherent motion) and to the center bar alone. In the majority of neurons center bar responses were suppressed by the texture surrounds. Two main effects were found. Some neurons were generally suppressed by either texture surround. Other neurons were less suppressed by texture displaying orientation or motion (i.e. feature) contrast than by the respective uniform texture, so that their responses to orientation or motion contrast appeared to be relatively enhanced (preference for feature contrast). General suppression was obtained in 33% of neurons tested for orientation and in 19% of neurons tested for motion. Preference for orientation or motion contrast was obtained in 22% and 34% of the neurons, respectively, and was also seen in the mean response of the population. One hundred nineteen neurons were studied in both orientation and motion tests. General suppression was correlated across the orientation and motion dimension, but not preference for feature contrast. We also distinguished modulatory effects from end-zones and flanks using butterfly-configured texture patterns. Both regions contributed to the generally suppressive effects. Preference for orientation or motion contrast was not generated from either end-zones or flanks exclusively. Neurons with preference for feature contrast may form the physiological basis of the perceptual saliency of pop-out elements in line textures. If so, pop-out of motion and pop-out of orientation would be encoded in different pools of neurons at the level of striate cortex.

scholarly journals Heading direction with respect to a reference point modulates place-cell activity

2018 ◽  
Author(s):  
P.E. Jercog ◽  
Y. Ahmadian ◽  
C. Woodruff ◽  
R. Deb-Sen ◽  
L.F. Abbott ◽  
...  
Keyword(s):  
Reference Point ◽  
Dorsal Hippocampus ◽  
Cell Activity ◽  
Pyramidal Cells ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Ca1 Pyramidal Cells ◽  
Electrophysiological Recordings ◽  
Heading Direction ◽  
Freely Moving

AbstractUtilizing electrophysiological recordings from CA1 pyramidal cells in freely moving mice, we find that a majority of neural responses are modulated by the heading-direction of the animal relative to a point within or outside their enclosure that we call a reference point. Our findings identify a novel representation in the neuronal responses in the dorsal hippocampus.

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