Understanding the functional consequences of synaptic specialization: insight from the Drosophila antennal lobe

Synapses exhibit diverse functional properties, and it seems likely that these properties are specialized to perform specific computations. The Drosophila antennal lobe provides a useful experimental preparation for exploring the relationship between synaptic physiology and neural computations. This review summarizes recent progress in describing synaptic properties in the Drosophila antennal lobe. These studies reveal that several types of synapses in this circuit are highly specialized, and that these specializations are in some cases under tight regulatory control. These synaptic specializations can be understood in terms of the computational features they confer on the circuit. Specifically, many of these properties appear to promote odor detection when odor concentrations are low, while promoting adaptive gain control when odor concentrations are high.

► Synapses in the Drosophila antennal lobe have diverse properties. ► The properties of these synapses can be understood as adaptive for the circuit. ► Afferent synapses appear to be specialized for strength and reliability. ► Synaptic inhibition seems to be specialized to prevent postsynaptic saturation. ► Recurrent excitatory synapses seem adapted to prevent runaway excitation.