Vohs Jenifer L, Chambers R Andrew, Krishnan Giri P, O'Donnell Brian F, Hetrick William P, Kaiser Samuel T, Berg Sarah, Morzorati Sandra L
Psychological and Brain Sciences, Indiana University, Bloomington, Ind., USA.
Neuropsychobiology. 2009;60(1):12-22. doi: 10.1159/000234813. Epub 2009 Aug 14.
BACKGROUND/AIMS: The neonatal ventral hippocampal lesion (NVHL) rat model shows biological and behavioral abnormalities similar to schizophrenia. Disturbed sensory gating reflects a consistent neurobiological abnormality in schizophrenia. Although of critical interest, sensory gating has not been evaluated in the NVHL model.
The N40 rat analog of the human P50 was measured to assess sensory response and gating in NVHL and sham rats. Epidural electrodes recorded evoked potentials (EPs), from which amplitudes, latencies, difference scores (S1-S2) and gating ratios (S2/S1) were assessed. Power and phase locking were computed for evoked EEG activity, to test for frequency-specific abnormalities.
Prolonged S1 N40 latency was detected in the NVHL group, but amplitude and power measures did not differ. NVHL rats demonstrated disturbed phase-locked sensory gating at theta and beta frequencies, as well as reduced phase-locked gamma activity across stimuli, most robustly at S1.
While measures of sensory gating obtained from the EP were relatively insensitive to the NVHL model, phase locking across trials was affected. NVHL rats may have increased evoked response temporal variability, similar to patients with schizophrenia. This pattern of findings likely reflects core developmental NVHL disturbances in dorsal hippocampal circuits associated with temporal and frontal areas.
背景/目的：新生大鼠腹侧海马损伤（NVHL）模型表现出与精神分裂症相似的生物学和行为异常。感觉门控障碍反映了精神分裂症中一种持续存在的神经生物学异常。尽管备受关注，但NVHL模型中尚未对感觉门控进行评估。
测量人类P50的大鼠类似物N40，以评估NVHL大鼠和假手术大鼠的感觉反应和门控。硬膜外电极记录诱发电位（EP），评估其振幅、潜伏期、差值分数（S1-S2）和门控比率（S2/S1）。计算诱发脑电图活动的功率和锁相，以测试频率特异性异常。
在NVHL组中检测到S1 N40潜伏期延长，但振幅和功率测量无差异。NVHL大鼠在θ和β频率上表现出锁相感觉门控障碍，并且在整个刺激过程中锁相γ活动减少，在S1时最为明显。
虽然从EP获得的感觉门控测量对NVHL模型相对不敏感，但试验间的锁相受到影响。NVHL大鼠可能具有增加的诱发反应时间变异性，类似于精神分裂症患者。这种发现模式可能反映了与颞叶和额叶区域相关的背侧海马回路中NVHL的核心发育障碍。
