Neuroscience - The neurobiology of slow synaptic transmission

Nerve cells communicate with each other through two mechanisms, referred to as fast and slow synaptic transmission. Fast-acting neurotransmitters, e.g ., glutamate (excitatory) and gamma -aminobutyric add (GABA) (inhibitory), achieve effects on their target cells within one millisecond by virtue of o pening ligand-operated ion channels. In contrast all of the effects of the biogenic amine and peptide neurotransmitters, as well as many of the effect s of glutamate and GABA are achieved over hundreds of milliseconds to minut es by slow synaptic transmission. This latter process is mediated through a n enormously more complicated sequence of biochemical steps, involving seco nd messengers, protein kinases, and protein phosphatases. Slow-acting neuro transmitters control the efficacy of fast synaptic transmission by regulati ng the efficiency of neurotransmitter release from presynaptic terminals an d by regulating the efficiency with which fast-acting neurotransmitters pro duce their effects on postsynaptic receptors.