Biomedical subjects

Dervila Glynn

Publications and source records attributed to Dervila Glynn.

3 recordsLinked to original sources

PubMed2006

Early motor development is abnormal in complexin 1 knockout mice.

Complexin I expression is dysregulated in a number of neurological diseases including schizophrenia and depression. Adult complexin 1 knockout (Cplx1(-/-)) mice are severely ataxic and show deficits in exploration and emotional reactivity. Here, we evaluated early behavioural development of Cplx1(-/-) mice. Cplx1(-/-) mice showed marked abnormalities. They develop ataxia by post-natal day 7 (P7), and by P21 show marked deficits in tasks requiring postural skills and complex movement. These deficits are consistent with abnormalities in sensory and motor development found in infants that develop schizophrenia in later life. A role for complexin I depletion should be considered in diseases where deficits in early sensory and motor development exist, such as autism and schizophrenia.

Adaptor Proteins, Vesicular Transport↗

PubMed2005

Profound ataxia in complexin I knockout mice masks a complex phenotype that includes exploratory and habituation deficits.

Complexins are presynaptic proteins that bind to the SNARE complex where they modulate neurotransmitter release. A number of studies report changes in complexins in psychiatric (schizophrenia and depression) and neurodegenerative disorders (Huntington's disease, Wernicke's encephalopathy and Parkinson's disease). Here, we characterize the behavioural phenotype of Cplx1 knockout (Cplx1-/-) mice. Cplx1-/- mice develop a strong ataxia in the absence of cerebellar degeneration. Although originally reported to die within 2-4 months after birth, when reared using an enhanced feeding regime, these mice survive normally (i.e. >2 years). Cplx1-/- mice show pronounced deficits in motor coordination and locomotion including abnormal gait, inability to run or swim, impaired rotarod performance, reduced neuromuscular strength, dystonia and resting tremor. Although the abnormal motor phenotype dominates their overt symptoms, Cplx1-/- mice also show other behavioural deficits, particularly in complex behaviours. They have deficits in grooming and rearing behaviour and show reduced exploration in several different paradigms. They also show deficits in tasks reflecting emotional reactivity. They fail to habituate to confinement and show a 'panic' response when exposed to water. The abnormalities seen in the behaviour of Cplx1-/- mice reflect those predicted from the distribution of complexin I in the brain. Our data show that complexin I is essential not only for normal motor function in mice, but also for normal performance of other complex behaviours. These results support the idea that altered expression of complexins in disease states may contribute to the symptomatology of disorders in which they are dysregulated.

Adaptor Proteins, Vesicular Transport↗

PubMed2003

Complexin II is essential for normal neurological function in mice.

Complexins (CPLXs) are modulators of synaptic vesicle release. At 1 year of age, CPLXII knockout (KO) mice appear normal. However, behavioral testing reveals underlying deficits of motor and cognitive function in these mice. We found motor deficits on the rotarod, and learning deficits in the Morris water maze (both acquisition and reversal) and the two-choice swim tank (reversal). The reversal learning deficits are particularly noticeable, being present from the earliest time of testing, when most other behaviors are normal. CPLXII KO mice also fail to develop adult patterns of exploratory behavior in the open field and show deficits in interactive grooming behaviors. The behavioral deficits worsen with age. For example, while rotarod performance is normal until 10 weeks, it is impaired from 24 weeks onwards. Similarly, deficits in spatial learning in the Morris water maze are mild at 8 weeks, but pronounced by 1 year of age. The deficits seen in CPLXII KO mice are not due to physical weakness, since their ability to run, swim and grip is unimpaired. Rather, the mice appear to have deficits of higher function. The deficits seen in CPLXII KO mice are strikingly similar to those seen in the R6/2 model of Huntington's disease (HD) where a progressive depletion of CPLXII is seen. This suggests that depletion of CPLXII contributes to cognitive abnormalities in R6/2 mice. Given that decreased expression of CPLXII is seen in HD and schizophrenic patients, a role for CPLXII depletion should be considered in other diseases where motor, cognitive and psychiatric symptoms co-exist.

Adaptor Proteins, Vesicular Transport↗