• injection of adenovirus expressing cre do not alter brain morphology, expression of midbrain dopamine neuron markers, or microglia activation (J:157098)

• in the dorsolateral striatum and areas innervated by scattered ventral tegmental area of mice injected with an adenovirus expressing cre

• mice injected with an adenovirus expressing cre exhibit a progressive decrease in dopaminergic neurons compared with wild-type mice

• 3 to 4 months after injection with an adenovirus expressing cre, mice exhibit impaired performance in a stepping test compared with wild-type mice

• in the dorsolateral striatum and areas innervated by scattered ventral tegmental area of mice injected with an adenovirus expressing cre

• mice do not survive beyond 3 weeks

• however, leaving pups with mothers improves perinatal survival beyond 3 weeks

• at P1, striatal dopamine levels are decreased to 14% of wild-type

• at P14, the ratio of homovanillic acid (HVA) to dopamine is increased indicating increased dopamine turnover compared to in wild-type mice

• at P60, striatal dopamine levels are almost completely lost unlike in wild-type mice

• at P60, dopamine levels are more severely decreased in the caudate putamen compared to in the nucleus accumbens

• expression of midbrain dopamine neuron markers is lost compared to in wild-type mice

• mice exhibit a rapid loss of substantia nigra pars compacta cell bodies with only scattered ventral tegmental area neurons remaining compared with wild-type mice

• at 4 and 14 months

• L-DOPA-treated mice exhibit hyperactivity unlike similarly treated wild-type mice

• L-DOPA-treated mice exhibit repetitive behaviors (including repetitive gnawing, excessive grooming, and self-injury) unlike similarly treated wild-type mice

• at P1, striatal dopamine levels are decreased to 14% of wild-type

• at P14, the ratio of homovanillic acid (HVA) to dopamine is increased indicating increased dopamine turnover compared to in wild-type mice

• at P60, striatal dopamine levels are almost completely lost unlike in wild-type mice

• at P60, dopamine levels are more severely decreased in the caudate putamen compared to in the nucleus accumbens

• serotonin levels in the caudate putamen and nucleus accumbens are increased compared to in wild-type mice

• L-DOPA-treated mice exhibit hyperactivity and repetitive behaviors unlike similarly treated wild-type mice

• at 2 months, mice left with their mothers after weaning are 40% smaller than wild-type mice