It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts a...It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and展开更多
Some shallow and middle optic tectum(OT)neurons have stable,asymmetric full-screen ON and OFF stimulus response properties,which makes them candidates for delay encoding.In this paper,we investigated the de...Some shallow and middle optic tectum(OT)neurons have stable,asymmetric full-screen ON and OFF stimulus response properties,which makes them candidates for delay encoding.In this paper,we investigated the delay encoding mechanism for the neuronal clusters in the OT region of pigeons and determined the mechanism of delay coding in the OT region.By analyzing the responses of the neuron cluster under full-screen switch-on and switch-off stimulation,we found that the delay coding was widespread in the OT region where the ON/OFF stimulation time difference was 4-6 ms.Information theory analysis under grating stimulation and experiments based on single-neuron character reconstruction of neurons showed that OT neuron clusters use the first spike latency(FSL)for the rapid transfer of spatial structure information.Furthermore,4 models were used to predict the first spike latency of these OT neurons.The best simulation results were obtained using an architecture where the ON and OFF paths of multiple retinal ganglion cells(RGCs)were integrated and summed,respectively.展开更多
Using the blind patch-clamp technique with the whole-cell mode, we have studied the modulation of pre-synaptic receptor on postsynaptic g-aminobutyric acid (GABA) receptor measuring miniature inhibitory postsy-naptic ...Using the blind patch-clamp technique with the whole-cell mode, we have studied the modulation of pre-synaptic receptor on postsynaptic g-aminobutyric acid (GABA) receptor measuring miniature inhibitory postsy-naptic currents (mIPSCs) in optic tectum of Xenopus during critical peroid. It was demonstrated that compared with mature neurons, mIPSCs recorded from immature neurons had smaller amplitude and longer decay time. mIPSCs are mediated by GABAa receptor. The nicotinic acetylcholine receptor agonists (carbachol, cytisine, nicotine, DMPP and so on) could increase the frequency of mIPSCs. The enhance-ment of mIPSCs frequency induced by nAChR agonists was calcium-dependent. However, the choline, a product of hy-drolyzed acetylcholine, could not increase the frequency of mIPSCs. DH-b-E, a competitive antagonist of nAChR, blocked the increase of mIPSCs frequency induced by car-bachol. Mecamyllamine, an a3b4 subtype of nAChR antago-nist, also blocked the carbachol-induced enhancement of mIPSCs. On the other hand, MLA, a7 subtype of nAChR antagonist, had no effect on it. Thus, it seems that nAChR could presynaptically modulate the mIPSCs and a3b4 sub-type of nAChR might be involved. But a7 nAChR subtype of nAChR would not be involved. The modulation is calcium- dependent. Meanwhile, we found that Ca2+-free solution could elicit giant PSCs. The frequency of mIPSCs also is related with the level of HP.展开更多
基金Project supported by the National Natural Science Foundation of China
文摘It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and
基金the National Natural Science Foundation of China(NSFC)General program(61673353)the Young Scientist Fund of NSFC(61603344)Key research projects of Higher Education of Henan Province of China(15A120017).
文摘Some shallow and middle optic tectum(OT)neurons have stable,asymmetric full-screen ON and OFF stimulus response properties,which makes them candidates for delay encoding.In this paper,we investigated the delay encoding mechanism for the neuronal clusters in the OT region of pigeons and determined the mechanism of delay coding in the OT region.By analyzing the responses of the neuron cluster under full-screen switch-on and switch-off stimulation,we found that the delay coding was widespread in the OT region where the ON/OFF stimulation time difference was 4-6 ms.Information theory analysis under grating stimulation and experiments based on single-neuron character reconstruction of neurons showed that OT neuron clusters use the first spike latency(FSL)for the rapid transfer of spatial structure information.Furthermore,4 models were used to predict the first spike latency of these OT neurons.The best simulation results were obtained using an architecture where the ON and OFF paths of multiple retinal ganglion cells(RGCs)were integrated and summed,respectively.
基金the Na-tional Natural Science Foundation of China (Grant No.39670774)
文摘Using the blind patch-clamp technique with the whole-cell mode, we have studied the modulation of pre-synaptic receptor on postsynaptic g-aminobutyric acid (GABA) receptor measuring miniature inhibitory postsy-naptic currents (mIPSCs) in optic tectum of Xenopus during critical peroid. It was demonstrated that compared with mature neurons, mIPSCs recorded from immature neurons had smaller amplitude and longer decay time. mIPSCs are mediated by GABAa receptor. The nicotinic acetylcholine receptor agonists (carbachol, cytisine, nicotine, DMPP and so on) could increase the frequency of mIPSCs. The enhance-ment of mIPSCs frequency induced by nAChR agonists was calcium-dependent. However, the choline, a product of hy-drolyzed acetylcholine, could not increase the frequency of mIPSCs. DH-b-E, a competitive antagonist of nAChR, blocked the increase of mIPSCs frequency induced by car-bachol. Mecamyllamine, an a3b4 subtype of nAChR antago-nist, also blocked the carbachol-induced enhancement of mIPSCs. On the other hand, MLA, a7 subtype of nAChR antagonist, had no effect on it. Thus, it seems that nAChR could presynaptically modulate the mIPSCs and a3b4 sub-type of nAChR might be involved. But a7 nAChR subtype of nAChR would not be involved. The modulation is calcium- dependent. Meanwhile, we found that Ca2+-free solution could elicit giant PSCs. The frequency of mIPSCs also is related with the level of HP.
