Neuronal activity, recording

Figure 1.9 Comparison of the effects of an endogenously released and exogenously applied neurotransmitter on neuronal activity (identity of action). Recordings are made either of neuronal firing (extracellularly, A) or of membrane potential (intracellularly, B). The proposed transmitter is applied by iontophoresis, although in a brain slice preparation it can be added to the bathing medium. In this instance the applied neurotransmitter produces an inhibition, like that of nerve stimulation, as monitored by both recordings and both are affected similarly by the antagonist. The applied neurotransmitter thus behaves like and is probably identical to that released from the nerve...

IL-ip is a well documented sleep factor (reviewed by Obal Krueger, 2003). Its administration increases sleep, its blockade decreases sleep and sleep rebound, and its transcription increases during waking. IL-1 receptor knock-out mice sleep less. Local application of IL-1 p in POA also stimulates NREM sleep. We examined the effects of local administration of IL-1 p and an antagonist through microdialytic application adjacent to lateral POA neurons (Alam et at, 2004). Neuronal activity is recorded within 0.5-1.0 mm of a microdialysis membrane in unrestrained rats. IL-ip potently inhibited the activity of 79% of wake-active neurons. The inhibitory response to IL-ip of wake-active neurons could be blocked by pre-treatment with IL-lra, an IL-ip antagonist. IL-ip application also excited some sleep-active neurons, but this response was inconsistent. 

Albino rats of the CF strain were kept on a diet containing 4% salt (sodium chloride) for 7 days. They were anaesthetized and fixed on a stereotaxic table. A glass coated silver microelectrode (tip 3.5 pm in diam, resistance 1.5 - 2.5 MG) was inserted into the lateral hypothalamic area and connected through a head-stage, a pre-amplifier and a filter to an oscilloscope. After recording the neuronal activity by a two-channel recorder for 5 min, Natrum mur 30 (Natrum muriaticum 30) and Natrum... 

Figure 6. Spontaneous and evoked spike activity recorded from taste neurons of the geniculate ganglion of the cat. The classification of the three different sensory neurons is indicated by Groups I, II, and III.

Schregardus DS, Pieneman AW, Ter Maat A, Jansen RF, Brouwer TJF, Gahr ML. A lightweight telemetry system for recording neuronal activity in freely behaving small animals. J. Neurosci. Methods. 2006 155 62-71. 

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