• Molecules and Cells
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• v.38 no.6
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• pp.540-547
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• 2015

Attention deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders, affecting approximately 5% of children. However, the neural mechanisms underlying its development and treatment are yet to be elucidated. In this study, we report that an ADHD mouse model, which harbors a deletion in the Git1 locus, exhibits severe astrocytosis in the globus pallidus (GP) and thalamic reticular nucleus (TRN), which send modulatory GABAergic inputs to the thalamus. A moderate level of astrocytosis was displayed in other regions of the basal ganglia pathway, including the ventrobasal thalamus and cortex, but not in other brain regions, such as the caudate putamen, basolateral amygdala, and hippocampal CA1. This basal ganglia circuit-selective astrocytosis was detected in both in adult (2-3 months old) and juvenile (4 weeks old) $Git1^{\check{s}/\check{s}}$ mice, suggesting a developmental origin. Astrocytes play an active role in the developing synaptic circuit; therefore, we performed an immunohistochemical analysis of synaptic markers. We detected increased and decreased levels of GABA and parvalbumin (PV), respectively, in the GP. This suggests that astrocytosis may alter synaptic transmission in the basal ganglia. Intriguingly, increased GABA expression colocalized with the astrocyte marker, GFAP, indicative of an astrocytic origin. Collectively, these results suggest that defects in basal ganglia circuitry, leading to impaired inhibitory modulation of the thalamus, are neural correlates for the ADHD-associated behavioral manifestations in $Git1^{\check{s}/\check{s}}$ mice.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.2
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• pp.212-218
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• 2005

Cigarette smoking has been known to have a few beneficial effects on some neuronal diseases such as Alzheimer's disease(AD), Parkinson's disease(PD) and prion disease by scrapie agent shows many similar properties with AD. In this respect, we investigated what biological effects are exerted by cigarette smoke exposure(CSE) in the brain of mouse infected by 87V scrapie. The scrapie agent was inoculated through stereotaxic microinjection of the homogenates of the scrapie agent infected brain into the intracerebral system in the 1M mice. The inoculation into mice typically exhibits neurochemical, physiological and histopathological characteristics of prion disease: loss of neurotransmitters and induction of astrocytosis and vacuolation in brain as well as reduction of spatial movement and loss of body weight. CSE led to alleviated the loss of body weight and also improved spatial movement of the infected mice. Most interestingly, CSE attenuated astrocytosis and vacuolation caused by scrapie infection in the brain. In addition, decreased levels of dopamine in striatal and hypothalamic regions as well as serotonin level in hippocampus caused by scrapie infection were also attenuated by exposure to cigarette smoke. These findings suggest that cigarette smoke, by its inhibition of astrocytosis and vacuolation followed by its restoration of levels of some neurotransmitters, may partly contribute to suppression in the progress of neurodegeneration caused by scrapie infection.

• Journal of Veterinary Clinics
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• v.21 no.1
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• pp.80-82
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• 2004

A 3 month-old male dog with clinical signs of anorexia, soft stool, ocular and nasal discharge, cough and respiratory distress was submitted to the Cheju National University for diagnosis. At necropsy, tan to pulp]e-red sublobar to lobar consolidations were presented in apical and cardiac lobe of lung. Histopathologically, severe diffuse bronchointerstitial pneumonia with necrotic bronchiolitis was noted in the lung. The demyelinating encephalitis and astrocytosis were presented in cerebellum and cerebrum. Numerous round, ovoid or cluster of tachyzoites were also identified in alveolar lumen, alveolar wall and cytoplasm of macrophages in the lung. The orgasnisms were demonstrated as Toxoplasma (T) gondii by immunohistochemistry. Intranuclear or intracytoplasmic eosinophilic inclusion bodies were seen in the glial cells of the cerebellum. Canine distemper virus (CDV) specific antigens were demonstrated in the cerebellum by the immunohistochemistry. In our knowledge, this is believed to be the first confirmed report of co-infection of CDV and T gondii in dog in Korea.

• Journal of Yeungnam Medical Science
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• v.19 no.2
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• pp.136-143
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• 2002

Even though the nonketotic hyperglycemia is a metabolic disorder, it complicates hemichorea-hemiballism rarely. Moreover, generalized chorea-ballism associated with nonketotic hyperglycemia in diabetes mellitus is very rare, so it has not been reported in Korean literature. Although the precise pathophysiologic mechanisms of these disorders are still poorly understood, deficiency of gamma aminobutyric acid (GABA) in nonketotic hyperglycemia or reduced GABAnergic inhibition by striatal lesion may increase inhibitory output to subthalamic nucleus. These result loss of pallidal inhibition and produce contralateral hemichorea-hemiballism. The striatal lesions, such as transient ischemia with reactive astrocytosis or small amount of petechial hemorrhage, are related with changes of magnetic resonance image (MRI) findings presumably. We report a diabetic old woman who developed generalized chorea-ballismus as a very rare complication of nonketotic hyperglycemia. Her brain MRI showed high signal intensity in left lentiform nucleus and right pallidum on T1 weighted images and low signal intensity in bilateral putamen on T2 weighted images with highly enhanced corresponding lesions on T1 weighted enhancement images.