Prosap^8k homozygotes are fully viable and fertile, without apparent morphological or developmental abnormalities, but adults present significant decreases in locomotor capacity, in olfactory acuity and in olfactory learning, but normal avoidance behavior upon electric shock stimuli, as compared to controls.

The larval mushroom body calyx glomeruli of Prosap^8k homozygotes and Prosap^8k/Prosap^D101 or Prosap^8k/Df(2R)8328 transheterozygotes are significantly smaller and uni-lobed (with no apparent protrusion), as compared to the multi-lobed, highly protruded glomeruli of controls; all these mutant calyx glomeruli present a severe decrease in the number of antennal lobe projection neuron presynaptic bouton protrusions (labeled by ChAt), as compared to controls. Similar but milder defects (in both the overall glomerular morphology and number of presynaptic boutons) are also detected in Prosap^8k heterozygotes.

Prosap^8k homozygotes also present several defects in the adult mushroom body calyx glomeruli, namely an uni-lobed appearance in virtually all microglomeruli, a severe decrease in the number of presynaptic bouton protrusions, a significant increase in the postsynaptic density length, a significant increase in the number of T-bars, a but no obvious defects in the postsynaptic density, and a significant increase in the number of misshapen/collapsed synapses, as compared to controls.

Prosap^8k homozygous larval neuromuscular junctions do not display any obvious ultrastructural abnormalities (including in postsynaptic density), but present a significant decrease in spontaneous excitatory junctional potential frequency, but no significant changes in evoked or spontaneous excitatory junctional potential amplitudes at 0.4 or 1.0 mM Ca[2+] concentrations, as compared to controls.