Noradrenergic enhancement of Ca 2+ responses of basal dendrites in layer 5 pyramidal neurons of the prefrontal cortex

• Published in: Neurochemistry international Vol. 51; no. 5; pp. 323 - 327
• Main Authors: Barth, Albert M.I., Vizi, E. Sylvester, Lendvai, Balazs
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2007
• Subjects: Calcium; Dendrite; Excitability; Noradrenaline; Propranolol; Pyramidal; Calcium; Pyramidal; Excitability; Propranolol; Noradrenaline; Dendrite
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/j.neuint.2007.05.008

Although the excitatory effects of noradrenaline have been thoroughly studied in the central nervous system, there is relatively little known about the adrenergic effects on Ca 2+ dynamics of dendrites. In the present study, we imaged basal dendrites of layer 5 pyramidal neurons in the prefrontal cortex using two-photon microscopy. In our experiments noradrenaline, applied in the bath, enhanced excitability of layer 5 pyramidal neurons. The number of evoked action potentials following current injection to the soma increased by 44.7% on average. In the basal dendrites and spines the evoked Ca 2+ responses were also markedly enhanced. Noradrenaline-induced effects could be blocked by the β-adrenergic blocker propranolol. Our data, that activation of the noradrenergic system increases excitability of layer 5 pyramidal neurons via β-adrenergic receptors and enhances Ca 2+ signaling in basal dendrites, suggest a cellular site of action for noradrenaline to improve the integrative capabilities of dendrites.