Phenotypes Associated with This Genotype

Genotype
MGI:5469876

• Allelic Composition: Syngap1^tm1Rlh/Syngap1⁺
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

nervous system

nervous system phenotype ( J:193208 )

N • at P14, mice exhibit normal medial perforant path release probability and intrinsic spiking of dentate gyrus neurons

increased susceptibility to pharmacologically induced seizures ( J:193208 )

• fluorothyl-induced

audiogenic seizures ( J:193208 )

abnormal dendrite morphology ( J:193208 )

• at P14, dentate gyrus neuron dendritic trees exhibit a decrease in the spatial volume compared with in wild-type mice

abnormal dendritic spine morphology ( J:193208 )

• larger spines by P14 and persisting into adulthood

• more mushroom-type spines and fewer stubby spines beginning in the second postnatal week

• spines are less motile at P14

• some spines exhibit a spontaneous increase in head volume

• however, spine density is normal

abnormal CNS synaptic transmission ( J:193208 )

• photosimulation-evoked signals originating in the dentate gyrus are amplified as they spread through the hippocampus unlike in wild-type mice

• synaptic transmission in the Schaeffer Collateral pathway in the CA1 is strong during early development compared with wild-type mice

• however, synaptic transmission in the Schaeffer Collateral pathway in the CA1 in adult mice is normal

abnormal excitatory postsynaptic potential ( J:193208 )

• by P14, field excitatory postsynaptic potential is increased compared to in control mice

• however, synaptic function at P9, P21 and later is normal

abnormal glutamate-mediated receptor currents ( J:193208 )

• at P14, mice exhibit an increase in the ratio of AMPA/NMDA currents in dentate gyrus granule neurons compared with wild-type mice

• however, NMDAR-evoked synaptic transmission is normal

enhanced AMPA-mediated synaptic currents ( J:193208 )

• increased sensitivity at P14

abnormal miniature excitatory postsynaptic currents ( J:193208 )

• increased amplitude and frequency at P14

• however, both are normal at P21

abnormal miniature inhibitory postsynaptic currents ( J:193208 )

• increased frequency and amplitude in the dentate gyrus neurons

increased miniature inhibitory postsynaptic current amplitude ( J:193208 )

• in the dentate gyrus neurons

increased miniature inhibitory postsynaptic current frequency ( J:193208 )

• in the dentate gyrus neurons

behavior/neurological

behavior/neurological phenotype ( J:193208 )

N • mice exhibit normal contextual fear memory

increased susceptibility to pharmacologically induced seizures ( J:193208 )

• fluorothyl-induced

abnormal discrimination learning ( J:193208 )

• mice are unable to discriminate between two contexts during contextual fear training unlike wild-type mice

hyperactivity ( J:193208 )

• in an open field at P14

audiogenic seizures ( J:193208 )