The physiological effects of alpha 1-adrenoceptors (alpha 1-ARs) have been examined in many brain regions. However, little is known about the mechanism of modulation on synaptic transmission by alpha 1-ARs in the medial prefrontal cortex (mPFC). The present study investigated how alpha(1)-AR activation regulates glutamatergic synaptic transmission in layer V/VI pyramidal cells of the rat mPFC. We found that the alpha(1)-AR agonist phenylephrine (Phe) induced a significant enhancement of the amplitude and frequency of miniature excitatory postsynaptic currents (mEPSCs). The facilitation effect of Phe on the frequency of mEPSCs involved a presynaptic protein kinase C-dependent pathway. Phe produced a significant enhancement on the amplitude of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA-R)- and N-methyl-d-aspartic acid receptor (NMDA-R)-mediated evoked excitatory postsynaptic currents (eEPSCs). Phe enhanced inward currents evoked by puff application of glutamate or NMDA. The Phe-induced facilitation of AMPA-R- and NMDA-R-mediated eEPSCs required, in part, postsynaptic G(q), phospholipase C and PKC. These findings suggest that alpha(1)-AR activation facilitates excitatory synaptic transmission in mPFC pyramidal cells via both pre- and post-synaptic PKC-dependent mechanisms.
[1]Fudan Univ, Inst Neurobiol, Shanghai 200032, Peoples R China.
[2]Fudan Univ, State Key Lab Med Neurobiol, Inst Brain Sci, Shanghai 200032, Peoples R China.
[3]Nanchang Univ, Inst Life Sci, Ctr Neuropsychiat Dis, Nanchang, Peoples R China.
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