Carbachol-induced presynaptic modulation of transmission from cortical layer 6 to posteromedial thalamic nucleus

• Autorzy: Nersisyan S. , Bekisz M. , Kubik E. , Granseth B. , Wrobel A.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: Thalamic relay cells constitute important node of reciprocal sensory processing which is highly dependent on current behavioral demands realized by brainstem neuromodulatory systems. In these experiments, performed on rats’ thalamic brain slices, we have investigated cholinergic influence on synaptic transmission from cortical layer 6 to the posteromedial thalamic nucleus (PoM). METHODS: Neuronal membrane potentials and currents were recorded with whole-cell patch-clamp method and general cholinergic agonist carbachol was added to the bath in order to mimic cholinergic activation. Excitatory postsynaptic responses were evoked in PoM cells by repetitive trains of 5 electrical stimuli delivered at 20 Hz through bipolar electrode placed at the corticothalamic fibers in the internal capsule. RESULTS: In all investigated cells, consecutive postsynaptic responses in the train showed pronounced frequency facilitation (i.e. increase in amplitude). Carbachol substantially decreased postsynaptic response amplitudes, but at the same time it enhanced the magnitude of frequency facilitation. Moreover, the amplitudes of each consecutive postsynaptic potential in the train were characterized by much higher trial-to-trial coefficient of variation (SD/ mean). These effects suggested presynaptic action of carbachol. To prove this, we measured the failure rate of excitatory postsynaptic currents in PoM cells in response to minimum stimulation of corticothalamic fibers. CONCLUSION: The substantial increase of failure rate in the presence of carbachol supports the hypothesis that observed effects of cholinergic modulation relay on decreased probability of transmitter release from presynaptic site. This research and SN were supported by the European Union Regional Development Fund through the Foundation for Polish Science within the frames of International PhD Program in Neurobiology.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S53-S54

Twórcy

autor

Nersisyan S.

• Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland

autor

Bekisz M.

• Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland

autor

Kubik E.

• Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland

autor

Granseth B.

• Linkoping University, Linkoping, Sweden

autor

Wrobel A.

• Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland