| Many articles have reported the sensory-related function of the limbic systemin recent years, as a key structure, the amygdaloid complex was considered to be thesource of action and motivation. It receives information that comes from varousnuclei and modulates the sensory information by its axon projection. It has reportedthat the amygdaloid complex exerts ianuence on the medial geniculate body and theauditory cortex. Not only the light evoked response of latera geniculate cells can bemodulated by the amygdaloid complex, but also their receptive field characterstics.The pathway of this modulating innuence is amygdala isual cortexateralgeniculate. However, this pathway has not been yet conformed by the histologicalresearch, and the amygdaloid influence at cortical level has not also been reported.The present work investigatcd the amygdaloid influence on the light evoked localfield potential and the response properties of single cell in visual area l of rabbits,and the projection from amygdaloid complex to visual area l also analyzed byretrograde tracing technology. All results of present study are as follows;(1) 98% cells (n=157) in visual area 1 had spontaneous activity and 95%(n=l65) cells gave rcsponsc to the light stimulation of contralateral eye. The unitdischarge of 97% and 3% light response cells was increased and decreasedrespectively after giving and canceling the light stimulation. Three types of "on","off", and"on-off" responscs were recorded from 122 Cells, its proportion was 100%,8%, and 82% respectively. The response latency veded from 10 ms to 700 ms, and70% neurons had their latcncy shorter than 40 ms.(2) The charactcristics or the receptive field of 108 neurons in visual area lwere invcstigated. One uniform cell was recorded and 12% cells were concentriccells. l8% cells exhibited sensitive to moving stimulation and 7% cells weredirection seIective cells. About 58% neurons were orientation selective cells, andmoSt of these cells preferred to the stimulus of horizontal orientation.(3) A weak local fieId potential that induced by electrical stimulation of thebasaI amygdaIoid comp1ex was observed on the suffoce of visual area l, and itslatency was only l --2 ms.(4) The light evoked loca1 field potential with latency 20 ms could be recordedon the surface of visual area l of the rabbit. It was inhibited with latency l0 ms andduration 20 ms after electrical stimulation of the basal amygdala.(5) The light evoked response of single cells in visual area l was inhibited orfacilitated by eIectrical stimulation of the basal amygdala. The proportion of theinhibited and facilitated cells (n=89) was 30% and l7%. The latency of theamygdaloid infiuence was 2~20 ms and the duration ranged from l0 to 78 ms.The latency of l0% cells was shorter than 5 ms and in 77% cells it varied froml0 ms to 20 ms.(6) Just only the "on" pin or the "off' part of the "on-off' response neuronsthat influenced by the basaI amygdaloid stimuIation was affected. These resuItsindicate that the "on-off' response of the neuron in visual area l is not only a simpleconvergence of the "on-off' response from the retina or the lateral geniculate body,but is an result of the integration of the neuron in visual area l. Moreover, theamygdaloid complex probably takes part in this process.(7) In addition, the sPontaneous discharge rate of 32% (n=35) neurons wasinnuenced by the basal amygdaloid stimulation, 23% and 9O/ of them was inhibitedand facilitated respectively(8)FoIIowing electricaI stimulation of the basal amygdal' the movementsensitivity of 25% neurons (n=20) in visual area l was altered. In 48 orientationneurons, l9O/o neurons changed their orientation selectivity by disaPpearing,narrowing orientation range, widening orientation range, shifting preferredorientation or aPpearing orientation selectivity after electrical stimulation of thebasal amygdala.(9) Retrogradly labeled pyramid...
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