Syn1, Syn2, and Syn3 are members of the synapsin family of neuronal phosphoproteins and localize to the membranes of synaptic vesicles. Synapsin proteins are associated with autism. The synapsin I, II, and III knockout alleles all have a neo cassette replacing exon 1 of their respective genes. Homozygous triple knockout (TKO) mice exhibit 
a decrease in the rate of synaptic depression during trains of stimuli and a reduction in the number of vesicles in reserve pool of excitatory synapses. In contrast, basal transmission at inhibitory synapses is reduced, but kinetics are unaffected and the total number of synapses is reduced. Behavioral phenotypes include delayed whisker, eye and ear reflexes, abnormalities in coordination and balance, especially in the hindpaws, and deficits in spatial learning and memory.
Beginning at two months of age, mice experience mild and transient spontaneous seizures. Homozygous mice are viable and fertile with no reported reproductive deficiency.

Homozygous synapsin I, II and III triple knockout mice exhibit seizures, behavioral defects and altered basal transmission at excitatory and inhibitory synapses. These mice may be useful in studying the role of synaptic transmission.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.