de Oliveira RB, Gravina FS, Lim R, Brichta AM, Callister RJ, van Helden DF. Developmental changes in pacemaker currents in mouse locus coeruleus neurons.
Brain Res 2011;
1425:27-36. [PMID:
22018689 DOI:
10.1016/j.brainres.2011.09.053]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 09/16/2011] [Accepted: 09/23/2011] [Indexed: 10/17/2022]
Abstract
The present study compares the electrophysiological properties and the primary pacemaker currents that flow during the interspike interval in locus coeruleus (LC) neurons from infant (P7-12 days) and young adult (8-12 weeks) mice. The magnitude of the primary pacemaker currents, which consist of an excitatory TTX-sensitive Na(+) current and an inhibitory voltage-dependent K(+) current, increased in parallel during development. We found no evidence for the involvement of hyperpolarization-activated (I(H)) or Ca(2+) currents in pacemaking in infant or adult LC neurons. The incidence of TTX-resistant spikes, observed during current clamp recordings, was greater in adult neurons. Neurons from adult animals also showed an increase in voltage fluctuations, during the interspike interval, as revealed in the presence of the K(+) channel blocker, 4-AP (1mM). In summary, our results suggest that mouse LC neurons undergo changes in basic electrophysiological properties during development that influence pacemaking and hence spontaneous firing in LC neurons.
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