[Responses of neurons and astrocytes in rat hippocampus to kainic acid-induced seizures].

OBJECTIVE: To investigate the time course of the responses of neurons and astrocytes in rat hippocampus (HI) to kainic acid (KA)-induced seizures in various regions. METHODS: By means immunohistochemical staining for anti-Fos protein and anti-glial fibrillary acidic protein (GFAP), the regional distribution of reactive neurons and astrocytes in the HI was observed at different time points after a unilateral stereotaxic microinjection of KA into the lateral ventricle of rats to cause limbic and generalized convulsive seizures. RESULTS: The injection of KA triggered limbic motor seizures including immobilization, staring, facial and jaw clonus ect. followed by recurrent generalized convulsive seizures. After KA-induced seizures, the GFAP-positive astrocytes and Fos-positive neurons were markedly increased in the HI. The increase of GFAP immunoreactivity was observed 30 min after the seizure onset, reaching the maximum at 1 h; the increase of Fos immunoreactivity was detected at 1 h after the onset, peaking at 2 h. CONCLUSION: The neurons and astrocytes in rat HI are highly active during seizures and the reactive astrocytes might play an important role in epileptogenesis.

Effect of kainate on the synaptic transmission in hippocampal CA1 region.

OBJECTIVE: To investigate the effect of activated kainate receptor on both the excitatory and inhibitory synaptic transmission in the neurons in the hippocampal CA1 region. METHOD: Blind whole-cell voltage-clamp recordings were performed on the CA1 pyramidal cells in adult rat hippocampal slices to examine and analyze the effect of bath-applied kainate (10 micromol/L) on CA1 afferent fiber-evoked excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents (IPSCs), respectively. RESULTS: Activation of kainate receptor significantly depressed both IPSCs (P <0.01) and EPSCs (P <0.01) in neurons in the hippocampus CA1 region. CONCLUSION: Activation of kainate receptors directly inhibit excitatory and inhibitory input in those neurons, which contributes to the development of epilepsy in the hippocampus by affecting the dynamic balance of the hippocampal neurons.

[Benign fibrous histiocytoma involving the skull: a case report and literature review].

OBJECTIVE: Benign fibrous histiocytomas (BFH) represent a rare group of tumors with a common origin from the tissue histiocytes, often causing pain and space-occupying effect. BFH of bone causes diagnostic difficulties due to its atypical clinical symptoms, radiographic features and cytological characteristics, which can be easily confused with other benign lesions such as non-ossifying fibroma (NOF), giant cell tumor (GCT), and fibrous dysplasia. The lesions are prone to relapse, and the patients often show poor response to radiotherapy and chemotherapy, therefore radical lesion resection should be the therapeutic target of this disease. This paper reported a case of BFH involving the skull and reviewed the associated literatures.