Arginine-vasopressin-expressing neurons in the murine suprachiasmatic nucleus exhibit a circadian rhythm in network coherence in vivo.

The suprachiasmatic nucleus (SCN) is composed of functionally distinct subpopulations of GABAergic neurons which form a neural network responsible for synchronizing most physiological and behavioral circadian rhythms in mammals. To date, little is known regarding which aspects of SCN rhythmicity are generated by individual SCN neurons, and which aspects result from neuronal interaction within a network. Here, we utilize in vivo miniaturized microscopy to measure fluorescent GCaMP-reported calcium dynamics in arginine vasopressin (AVP)-expressing neurons in the intact SCN of awake, behaving mice.

Non-rapid eye movement sleep determines resilience to social stress.

Resilience, the ability to overcome stressful conditions, is found in most mammals and varies significantly among individuals. A lack of resilience can lead to the development of neuropsychiatric and sleep disorders, often within the same individual. Despite extensive research into the brain mechanisms causing maladaptive behavioral-responses to stress, it is not clear why some individuals exhibit resilience.

Decreased neuronal bursting and phase synchrony in the hippocampus of streptozotocin diabetic rats.

Diabetic encephalopathy is one of the complications of diabetes. Cognitive dysfunction is the main consequence. Previous findings from neuroanatomical and in vitro electrophysiological studies showed that the structure and function of the hippocampus is impaired in diabetes, which may underlie the cognitive dysfunction induced by diabetes.

Dissociated behavior of low-frequency responses and high-frequency oscillations after systemic morphine administration in conscious rats.

It has been proposed that high-frequency oscillations (HFOs) and underlying conventional somatosensory-evoked potentials (SEPs) have different brain origins. To further explore the neural mechanism of HFOs, we recorded the SEPs responding to high-intensity electrical stimulation applied to the hind paw of conscious, freely moving rats. We also investigated the effect of systemic morphine on HFOs and the conventional SEPs.

Impaired neural coordination in hippocampus of diabetic rat.

In vitro electrical neurophysiological and behavioural studies have shown that diabetes mellitus negatively affects hippocampal function. In this study, by using in vivo extracellular recording, the spontaneous neural activity was obtained from hippocampus of anaesthetized rats in both streptozotocin-induced diabetes group and normal control group. Temporal relationship between neuronal firing and slow oscillation (1-4 Hz) of local field potentials (LFPs) in hippocampus was analyzed using coherence and phase locking measurement.

[In vivo extracellular neural recording for the study of cortical plasticity].

Neural network plasticity is fundamental for learning and memory. Its abnormal change underlies some neural diseases. Measurement of the plasticity of cortex can help understand the mechanism of plasticity, and provide a quantitative way to observe the neural process of natural aging and neurodegenerative diseases, which may lead to a new approach for evaluation of anti-aging drugs and new medical treatments for neurodegenerative diseases.

Dynamic processing of nociception in cortical network in conscious rats: a laser-evoked field potential study.

(1) Field potential study in conscious rats provides a convenient and effective animal model for pain mechanism and pharmacological research. However, the spatial-temporal character of nociception processing in cortex revealed by field potential technique in conscious rats remains unclear. (2) In the present study, multi-channel field potentials evoked by noxious laser stimulation applied to the hind paw of conscious rats were recorded through 12 chronically implanted skull electrodes.

A comparison between spontaneous electroencephalographic activities induced by morphine and morphine-related environment in rats.

Previous studies demonstrated that drug cues could elicit drug-like or withdrawal-like effect, both subjectively and physiologically. However, few studies have compared the central activities induced by a drug-related environment and the drug itself. The aim of this study was to observe and compare electroencephalographic (EEG) changes induced by acute morphine administration and by the morphine-related environment.