In vivo intracellular responses of the medial geniculate neurones to acoustic stimuli in anaesthetized guinea pigs

摘要: In the present study, we investigated auditory response features of medial geniculate neurones, using in vivo intracellular recordings anaesthetized guinea pigs. Of 76 neurones examined, 9 showed ‘off’ or ‘on–off’ responses to an acoustic stimulus and thus were defined as neurones. Among remaining 67 42 excitatory postsynaptic potential (EPSP) stimuli 25 either a pure inhibitory (IPSP, 7 neurones), IPSP preceded by EPSP (EPSP–IPSP type, 18 neurones). The exhibited mean latency 15.7 ± 6.1 ms, which was significantly shorter than that (21.3 8.6 P < 0.01). also greater duration (208.5 128.2 ms versus 122.4 84.8 0.05), while there no significant differences between amplitudes (8.3 3.2 mV 8.7 5.3 mV). 11 histologically labelled, located lemniscal body (MGB) 4 non-lemniscal MGB. Another 6 labelled With membrane above −72 mV, when their depolarized. However, upon hyperpolarization below −74 shifted low-threshold calcium spikes (LTS)/LTS bursts. different durations, responded offset MGB latencies deviations addition exhibiting numbers spikes, suggesting timing could be another component utilized thalamic encode information on stimulus. Given some are multisensory project entire cortex, selective corticofugal inhibition would enable ascending pathway prepare cortex receive subsequent information, avoiding interference other sensory inputs.