Final answer:
Synaptic GABAA receptors are responsible for phasic inhibition, while extra-synaptic GABAA receptors are associated with tonic inhibition. The answer is a) Phasic; Tonic. Both types of inhibitions are critical for neural network balance.
Step-by-step explanation:
Synaptic GABAA receptors maintain phasic inhibition, while extra-synaptic GABAA receptors maintain tonic inhibition. The correct answer is therefore a) Phasic; Tonic. In the context of GABAergic neurotransmission, phasic inhibition refers to the rapid, transient inhibitory effects that are mediated by the activation of synaptic GABAA receptors. These receptors respond to the sudden release of GABA from synaptic vesicles into the synaptic cleft.
In contrast, tonic inhibition is a sustained inhibitory effect that arises from the constant activation of extra-synaptic GABAA receptors, which detect the presence of ambient GABA in the extracellular space. Both phasic and tonic inhibitory currents play crucial roles in maintaining the balance between excitation and inhibition within neuronal networks, which is essential for proper brain function and the prevention of neurological disorders such as epilepsy and schizophrenia.