Publication Date:
2011-12-27
Description:
An unusual feature of the cerebellar cortex is that its output neurons, Purkinje cells, release GABA (gamma-aminobutyric acid). Their high intrinsic firing rates (50 Hz) and extensive convergence predict that their target neurons in the cerebellar nuclei would be largely inhibited unless Purkinje cells pause their spiking, yet Purkinje and nuclear neuron firing rates do not always vary inversely. One indication of how these synapses transmit information is that populations of Purkinje neurons synchronize their spikes during cerebellar behaviours. If nuclear neurons respond to Purkinje synchrony, they may encode signals from subsets of inhibitory inputs. Here we show in weanling and adult mice that nuclear neurons transmit the timing of synchronous Purkinje afferent spikes, owing to modest Purkinje-to-nuclear convergence ratios ( approximately 40:1), fast inhibitory postsynaptic current kinetics (tau(decay) = 2.5 ms) and high intrinsic firing rates ( approximately 90 Hz). In vitro, dynamically clamped asynchronous inhibitory postsynaptic potentials mimicking Purkinje afferents suppress nuclear cell spiking, whereas synchronous inhibitory postsynaptic potentials entrain nuclear cell spiking. With partial synchrony, nuclear neurons time-lock their spikes to the synchronous subpopulation of inputs, even when only 2 out of 40 afferents synchronize. In vivo, nuclear neurons reliably phase-lock to regular trains of molecular layer stimulation. Thus, cerebellar nuclear neurons can preferentially relay the spike timing of synchronized Purkinje cells to downstream premotor areas.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3268051/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3268051/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Person, Abigail L -- Raman, Indira M -- F32 NS067831/NS/NINDS NIH HHS/ -- F32 NS067831-02/NS/NINDS NIH HHS/ -- F32-NS067831/NS/NINDS NIH HHS/ -- R01 NS039395/NS/NINDS NIH HHS/ -- R01 NS039395-13/NS/NINDS NIH HHS/ -- R01-NS39395/NS/NINDS NIH HHS/ -- England -- Nature. 2011 Dec 25;481(7382):502-5. doi: 10.1038/nature10732.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA. a-person@northwestern.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22198670" target="_blank"〉PubMed〈/a〉
Keywords:
Action Potentials/physiology
;
Animals
;
Cerebellar Cortex/cytology
;
Cerebellar Nuclei/*physiology
;
Inhibitory Postsynaptic Potentials/*physiology
;
Kinetics
;
Mice
;
Mice, Inbred C57BL
;
Purkinje Cells/*physiology
;
Time Factors
;
Weaning
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
