Phenotypes Associated with This Genotype

Genotype
MGI:6157967

• Allelic Composition: Tcf4^tm1Hmb/Tcf4⁺; Tmem163^{Tg(ACTB-cre)2Mrt}/Tmem163⁺
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6 * FVB/N

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

growth/size/body

decreased body weight ( J:254983 )

behavior/neurological

abnormal habituation to a new environment ( J:254983 )

• mice show a similar level of activity at the outset of the task as controls, but the level of activity appears to wane more slowly, indicating a possible deficit in habituation to novel environments

impaired spatial learning ( J:254983 )

• mice take a longer time to locate the hidden platform in the Morris water maze task and travel farther during the acquisition phase than controls

• during the reversal phase of the hidden platform test, mice never meet the criterion for learning across the entire regimen, and they travel farther than controls

decreased anxiety-related response ( J:254983 )

• mice spend more time in the center region of the novel open field during the last 20 min of the trial, indicating reduced anxiety

• in the elevated plus maze task, mice spend more time in the open arms and make more entries into the open arm than closed arm, indicating reduced anxiety

decreased startle reflex ( J:254983 )

• mice exhibit a reduced startle to a 74 dB stimulus at both 12 and 19 weeks of age

increased locomotor activity ( J:254983 )

• mice exhibit increased activity and total distance traveled in the open field task

• however, mice exhibit normal motor coordination in the accelerating rotarod and normal sociability in the three-chamber task

nervous system

enhanced NMDA-mediated synaptic currents ( J:254983 )

• NMDA/AMPA current ratio is enhanced and because AMPA receptor-mediated synaptic transmission appears intact, this suggests that NMDAR-mediated currents are selectively enhanced

enhanced long-term potentiation ( J:254983 )

• mice exhibit enhanced long term potentiation (LTP) after 3 1 second bursts of 100 Hz stimulation and LTP is consistently enhanced over a range of stimulation frequencies

• however, no differences are seen in long term depression (LTD) after 15 min of 1 Hz stimulation, presynaptic function and AMPA receptor-mediated synaptic transmission appear normal in hippocampal area CA1, and short-term plasticity in terms of the paired-pulse ratio appears normal

decreased prepulse inhibition ( J:254983 )

• percentage prepulse inhibition is decreased in 19 week old mice but not 12-week old mice

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Pitt-Hopkins syndrome		DOID:0060488	OMIM:610954	J:254983