Ocular manifestations of internal carotid artery dissection.

Internal carotid artery dissection (ICAD) results from disruption of the intima of the arterial wall, and can lead to intrusion of blood into the arterial wall and form an intramural hematoma. The hematoma can compress the true lumen of the vessel, causing functional stenosis or occlusion. The classic triad signs of ICAD include pain in the ipsilateral neck, head and orbital regions; a (partial) Horner syndrome; and cerebral or retinal ischemia. However, not all ICAD patients present with this classic signs. In some cases, ocular manifestations are the initial (and sometimes the only) findings. We summarize the ocular manifestations associated with ICAD in 3 categories: visual symptoms, oculosympathetic palsy, and ocular motor nerve palsy.

[Developmental changes of spontaneous excitatory postsynaptic currents mediated by AMPA receptor in layer 2 and 3 pyramidal neurons of rat visual cortex].

OBJECTIVE: To investigate the modification function of visual experience onto synapses by recording developmental changes of spontaneous excitatory postsynaptic currents (sEPSC) in layer 2 and 3 pyramidal neurons of rat visual cortex, and to observe the spontaneous synaptic activities during the earlier postnatal period. METHODS: This was an experimental study. By combining infrared differential interference contrast (IR-DIC) technique and a CCD-camera system with visual patch clamp whole-cell recording technique, spontaneous EPSCs of P2 approximately 7, P8 approximately 14, P15 approximately 21 and P22 approximately 28 groups were observed and analyzed. The neurons were stained by adding 0.3% Lucifer yellow to the pipette solution simultaneously. RESULTS: The amplitude of sEPSC was enhanced when aging (F = 20.69, P < 0.01). The sEPSC frequency increased with age (F = 87.46, P < 0.01). There was no significant difference between P2 approximately 7 groups and P8 approximately 14 groups (P > 0.05). The electrophysiology and dendrite of neuron became mature whilst development. CONCLUSIONS: During the early postnatal days neurons were relatively immature, and became mature during development. Visual experience played an important role in this process. In spite of most synapses were taken silent at early postnatal days, and NMDA receptor-mediated function was revealed exclusively, these results suggested that early AMPA receptor-mediated functional activities existed in layer 2 and 3 pyramidal neurons. Synapses were not completely silent, but had early spontaneous activities.

[The changes of AMPA receptors subunit GluR2 and mEPSCs in visual cortex of monocular deprivation rats].

OBJECTIVE: To observe the change of expression in quantity of AMPA receptor subunit GluR2 and mEPSCs from monocular derivated rats. The preparative work was conducted for the further study on mechanism involved in regulation and control of the visual development plasticity. METHODS: It was an experimental study. Forty 14 d healthy Wistar rats were divided into two groups randomly; twenty in each group which were divided into two groups (I, II) and derivated monocular in experiment group (group I), and then were killed at a week later. ForIA and IIA 5 microm thick section was cut from tissue of visual cortex in coronary side, then the expression of GluR2 was observed by microscope and image analyze of GluR2 was conducted after immunohistochemical staining; for IB and IIB, mEPSCs was investigated which was used Voltage-clamp technique with whole-cell mode. RESULT: The level of GluR2 in visual cortex of normal rats was higher than experiment group. The mean amplitude and frequency of mEPSCs increased in the derivated monocular group. CONCLUSIONS: The level of GluR2 has changed association with the visual stimulation, which suggests that GluR2 should have the important physiological function on the postnatal development of visual system of rats.