Muscarinic Cholinergic Inhibition of Glutamatergic Transmission

摘要: The earliest studies of the actions acetylcholine (ACh) in brain indicated that cholinergic agonists had an excitatory effect. Local applications ACh to cerebral cortex increased amplitude electroencephalogram responses (Sjostrand, 1937) and could induce bursts spikes (Chatfield Dempsey, 1941), while intracisternal injections elicited seizures (Brenner Merritt, 1942). A systematic study neurons demonstrated ionophoretically applied excite discharges about 15% cells tested (Krnjevic Phillis, 1962; Krnjevic 1963a). a long latency, modest amplitude, duration, pharmacological profile consistent with activation muscarinic receptors 1963b). Later intracellular recordings this effect be associated depolarization decrease potassium conductance (Bernardo Prince, 1982; Halliwell Adams, 1982). These are stark contrast depressant effects observed on evoked synaptic activity. were noted some experiments using slice preparation (Yamamoto Kawai, 1967), it was speculated locus action for might presynaptic terminal. This proposition has been hard demonstrate directly because inaccessibility terminal experimental manipulations; consequently, postsynaptic membrane currents have more fully analyzed.