GABAergic neurons in the medial septum-diagonal band of Broca (MSDB) are important for acquisition of the classically conditioned eyeblink response.

The medial septum and diagonal band of Broca (MSDB) influence hippocampal function through cholinergic, GABAergic, and glutamatergic septohippocampal neurons. Non-selective damage of the MSDB or intraseptal scopolamine impairs classical conditioning of the eyeblink response (CCER). Scopolamine preferentially inhibits GABAergic MSDB neurons suggesting that these neurons may be an important modulator of delay CCER, a form of CCER not dependent on the hippocampus. The current study directly examined the importance of GABAergic MSDB neurons in acquisition of delay CCER. Adult male Sprague-Dawley rats received either a sham (PBS) or GABAergic MSDB lesion using GAT1-saporin (SAP). Rats were given two consecutive days of delay eyeblink conditioning with 100 conditioned stimulus-unconditioned stimulus paired trials. Intraseptal GAT1-SAP impaired acquisition of CCER. The impairment was observed on the first day with sham and lesion groups reaching similar performance by the end of the second day. Our results provide evidence that GABAergic MSDB neurons are an important modulator of delay CCER. The pathways by which MSDB neurons influence the neural circuits necessary for delay CCER are discussed.

In vivo Reflectance Confocal Microscopy: A Useful Tool to Select the Location of a Punch Biopsy in a Large, Clinically Indistinctive Lesion.

Reflectance confocal microscopy (RCM) is a noninvasive technique for in vivo imaging of the skin that allows evaluation of the total lesion area. This case report about a 66-year-old patient with a clinically indistinctive, previously treated erythematous lesion on the frontal part of the face demonstrates the use of RCM to select the proper biopsy location.

The role of cholinergic and GABAergic medial septal/diagonal band cell populations in the emergence of diencephalic amnesia.

The septohippocampal pathway, which is mostly composed of cholinergic and GABAergic projections between the medial septum/diagonal band (MS/DB) and the hippocampus, has an established role in learning, memory and disorders of cognition. In Wernicke-Korsakoff's syndrome (WKS) and the animal model of the disorder, pyrithiamine-induced thiamine deficiency (PTD), there is both diencephalic damage and basal forebrain cell loss that could contribute to the amnesic state. In the current experiment, we used the PTD animal model to access both cholinergic (choline acetyltransferase [ChAT] immunopositive) and GABAergic (parvalbumin [PV]; calbindin [CaBP]) neuronal loss in the MS/DB in relationship to midline-thalamic pathology. In addition, to gain an understanding about the role of such neuropathology in behavioral dysfunction, animals were tested on a non-rewarded spontaneous alternation task and behavioral performance was correlated to neuropathology. Unbiased stereological assessment of neuronal populations revealed that ChAT-positive neurons were significantly reduced in PTD rats, relative to control pair-fed rats, and thalamic mass and behavioral performance correlated with ChAT neuronal estimates. In contrast, both the PV- and CaBP-positive neurons in the MS/DB were not affected by PTD treatment. These results support an interactive role of both thalamic pathology and cholinergic cell loss in diencephalic amnesia.

Periodic faraday bias and lock-in phenomena in a laser gyro.

A simple theoretical description of coupling phenomena in a laser gyro has been developed. In particular, this allows the calculation of the residual nonlinearity of the response of the laser gyro in the presence of a periodic bias. A laser gyro has been constructed in a CER-VIT block. To solve the lock-in zone problem this detector contains a periodic bias system using the Faraday effect. The results of a number of trials are reported. In particular, we obtain experimental values of residual error due to coupling phenomena for each rotational speed. These results are in good agreement with a simple coupled oscillators theory.