Phenotypes Associated with This Genotype

Genotype
MGI:3620556

• Allelic Composition: Maoa^{Tg(H2-K1-Ifnb1)8Seif}/?
• Genetic Background: involves: C3H/HeJ

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

homeostasis/metabolism

abnormal circulating hormone level ( J:106365 )

• plasma corticosterone increase in cold, restraint, water deprivation and chronic variable stress is attenuated in knockouts compared to control C3H animals; psychosocial stress produces hypothalamic-pituitary-adrenal system activation to similar extent in control and mutant animals

increased dopamine level ( J:26232 )

• females show increased levels of dopamine in their brains

increased noradrenaline level ( J:26232 )

• females have elevated levels in the brain

increased serotonin level ( J:26232 , J:78281 )

• females have elevated serotonin levels in their brains (J:26232)

• levels are 4- and 1.5-fold higher in the brainstem and cervical spinal cord at E20 compared to control C3H animals; at P5, levels are 8- and 3.5-fold higher in brainstem and spinal cord compared to controls; at E18.5. there is a 4.8- and 6.5-fold increase in levels compared to C3H control (J:78281)

behavior/neurological

abnormal behavior ( J:26232 )

• in the open field test, female adults spend increased time in the center with hesitation about which direction to take (although if this is due to sensory or cognitive deficits or reduced fear is not known); for 12-week old mice, both male and female mutants spent significantly greater time in the center than did controls

• between days 11 and 16, animals run frantically and fall over

abnormal eating behavior ( J:26232 )

• i.p. injection of MAOB inhibitors into female adult mutants disrupts feeding

increased aggression towards humans ( J:26232 )

• between days 11 and 16, females have a greater tendency to bite the experimenter

abnormal depression-related behavior ( J:26232 )

• in the Porsolt's swim test, female adults make persistent attempts to escape, whereas controls spend more time floating; 9-week old female mutants spend significantly reduced time immobile in the water compared to control C3H animals

increased fear-related response ( J:26232 )

• between days 11 and 16, females promptly dig to hide under shavings in response to moderate sound and movement

abnormal grooming behavior ( J:26232 )

• i.p. injection of MAOB inhibitors into female adult mutants disrupts self-grooming

abnormal motor coordination/balance ( J:26232 )

• between days 5 and 10, when placed on a new surface, females move backward instead of pivoting

impaired righting response ( J:26232 )

• between days 5 and 10, animals display prolonged righting compared to C3H controls

impaired balance ( J:26232 )

• between days 11 and 16, animals run frantically and fall over

• in a beam-walking test, female adults grasp the edge of the beam with their hindlimbs whereas C3H adults are sure footed

hunched posture ( J:26232 )

• between days 11 and 16, females have a hunched posture

head bobbing ( J:26232 )

• neonates display intense head nodding behavior

abnormal sleep pattern ( J:26232 )

• between days 11 and 16, sleep in females is accompanied by violent shaking and jumps dispersing littermates

hyperresponsive ( J:26232 )

• between days 5 and 10, females display prolonged, stronger reactions to pinching

abnormal social/conspecific interaction behavior ( J:26232 )

• i.p. injection of MAOB inhibitors into female adult mutants disrupts social interaction

nervous system

abnormal cerebral cortex morphology ( J:26232 )

• somatosensory cortex of female mutant pups and adults display complete absence of cylindrical aggregates of granule cells (barrels) in layer IV

abnormal motor neuron morphology ( J:78281 )

• in transgenic neonates, the dendritic morphology of the phrenic neurons is a multipolar tree rather than a bipolar dendritic tree in C3H controls; the number of distal dendrites is significantly greater in the transgenic neonates

• phrenic motor neurons in transgenics possess dendritic spines and swollen varicosities with a greater frequency than in C3H

abnormal nervous system electrophysiology ( J:78281 )

• in brainstem-spinal cord preparations from transgenic mice, isolated respiratory centers produce phrenic nerve bursts that are more variable in cycle duration and amplitude (quantified as coefficients of variability, CVd) than in C3H controls; treatment of dams with a 5-HT synthesis inhibitor from E18 to birth decreases the CVd variability in neonates

• treatment of pregnant control dams with a 5-HT receptor agonist from P18 to birth significantly increased the mean CVd of neonates compared to untreated controls, while treatment of pregnant mutant dams with a 5-HT receptor antagonist resulted in lowering of the CVd in P0-2 transgenic neonates compared to control transgenic neonates

• application of exogenous 5-HT to the medulla does not affect the phrenic burst frequency in P0-3 transgenic neonates, while in conrol C3H neonates, there is a dose-dependent increase in burst frequency