Effects of Cannabis Consumption on Sleep.

Despite the fact that medical properties of Cannabis have been recognized for more than 5000 years, the use of Cannabis for medical purposes have recently reemerged and became more accessible. Cannabis is usually employed as a self-medication for the treatment of insomnia disorder. However, the effects of Cannabis on sleep depend on multiple factors such as metabolomic composition of the plant, dosage and route of administration.

Melanin-concentrating hormone (MCH) in the median raphe nucleus: Fibers, receptors and cellular effects.

Serotonergic neurons of the median raphe nucleus (MnR) and hypothalamic melanin-concentrating hormone (MCH)-containing neurons, have been involved in the control of REM sleep and mood. In the present study, we examined in rats and cats the anatomical relationship between MCH-containing fibers and MnR neurons, as well as the presence of MCHergic receptors in these neurons. In addition, by means of in vivo unit recording in urethane anesthetized rats, we determined the effects of MCH in MnR neuronal firing.

Vaporized Cannabis differentially modulates sexual behavior of female rats according to the dose.

Studies exploring the effect of compounds that modulate the endocannabinoid system on sexual behavior have yielded contradictory results. However, the effect of smoked Cannabis in women has been consistently associated with an increase in sexual drive. Therefore, it can be speculated that vaporized Cannabis will augment sexually motivated components of the sexual behavior of female rats.

Acute effect of vaporized Cannabis on sleep and electrocortical activity.

The use of Cannabis for medical purposes is rapidly expanding and is usually employed as a self-medication for the treatment of insomnia disorder. However, the effect on sleep seems to depend on multiple factors such as composition of the Cannabis, dosage and route of administration. Vaporization is the recommended route for the administration of Cannabis for medical purposes; however, there is no published research about the effects of vaporized Cannabis on sleep, neither in laboratory animals, nor in humans.

EEG dissociation induced by muscarinic receptor antagonists: Coherent 40 Hz oscillations in a background of slow waves and spindles.

Mesopontine and basal forebrain cholinergic neurons are involved in the control of behavioral states and cognitive functions. Animals treated with cholinergic muscarinic receptor antagonists display a dissociated state characterized by behavioral wakefulness (W) associated with high amplitude slow oscillations and spindles in the electroencephalogram (EEG), similar to those that occur during non-REM (NREM) sleep. Oscillations in the gamma frequency band (≈ 40 Hz) of the EEG also play a critical role during W and cognition.

Caffeine as an adulterant of coca paste seized samples: preclinical study on the rat sleep-wake cycle.

Caffeine is a common active adulterant found in illicit drugs of abuse, including coca paste (CP). CP is a smokable form of cocaine mainly consumed in South America, produced during the cocaine-extraction process. CP has high abuse liability and its chronic consumption induces severe sleep-wake alterations.

Power and coherence of cortical high-frequency oscillations during wakefulness and sleep.

Recently, a novel type of fast cortical oscillatory activity that occurs between 110 and 160 Hz (high-frequency oscillations (HFO)) was described. HFO are modulated by the theta rhythm in hippocampus and neocortex during active wakefulness and REM sleep. As theta-HFO coupling increases during REM, a role for HFO in memory consolidation has been proposed.

Neocortical 40 Hz oscillations during carbachol-induced rapid eye movement sleep and cataplexy.

Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the gamma band (30-45 Hz) of the electroencephalogram (EEG) have been involved in these cognitive functions. In previous studies, we analysed the extent of functional connectivity between cortical areas employing the 'mean squared coherence' analysis of the EEG gamma band.

Heart rate variability during carbachol-induced REM sleep and cataplexy.

The nucleus pontis oralis (NPO) exerts an executive control over REM sleep. Cholinergic input to the NPO is critical for REM sleep generation. In the cat, a single microinjection of carbachol (a cholinergic agonist) into the NPO produces either REM sleep (REMc) or wakefulness with muscle atonia (cataplexy, CA).

Coherent neocortical gamma oscillations decrease during REM sleep in the rat.

Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the high frequency band (30-100 Hz) of the electroencephalogram (EEG), that have been postulated to be a product of this interaction, are involved in the binding of spatially separated but temporally correlated neural events, which results in a unified perceptual experience. The extent of this functional connectivity can be examined by means of the mathematical algorithm called "coherence", which is correlated with the "strength" of functional interactions between cortical areas.

Melanin-concentrating hormone (MCH) modulates the activity of dorsal raphe neurons.

Hypothalamic neurons that utilize melanin-concentrating hormone (MCH) as a neuromodulator are localized in the postero-lateral hypothalamus and incerto-hypothalamic area. These neurons send dense projections to the dorsal raphe nucleus (DRN). Serotonergic neurons of the DRN are involved in the control of sleep and play a critical role in major depression.

Statistical, spectral and non-linear analysis of the heart rate variability during wakefulness and sleep.

As a first step in a program designed to study the central control of the heart rate variability (HRV) during sleep, we conducted polysomnographic and electrocardiogram recordings on chronically-prepared cats during semi- restricted conditions. We found that the tachogram, i.e.

Inter-hemispheric coherence of neocortical gamma oscillations during sleep and wakefulness.

Oscillations in the gamma frequency band (mainly ≈40 Hz) of the electroencephalogram (EEG) have been involved in the binding of spatially separated but temporally correlated neural events that result in a unified perceptual experience. The extent of these interactions can be examined by means of a mathematical algorithm called "coherence", which reflects the "strength" of functional interactions between cortical areas. As a continuation of a previous study of our group, the present study was conducted to analyze the inter-hemispheric coherence of the EEG gamma frequency band in the cat during alert wakefulness (AW), quiet wakefulness (QW), non-REM (NREM) sleep and REM sleep.

Wakefulness-promoting role of the inferior colliculus.

The inferior colliculus (IC) is a mesencephalic auditory nucleus involved in several functions including the analysis of the frequency and intensity of sounds as well as sound localization. In addition to auditory processes, the IC controls the expression of defensive responses. The objective of the present study was to test the hypothesis that the IC contributes to the maintenance of wakefulness.

Coherent neocortical 40-Hz oscillations are not present during REM sleep.

During cognitive processes there are extensive interactions between various regions of the cerebral cortex. Oscillations in the gamma frequency band (≈40 Hz) of the electroencephalogram (EEG) are involved in the binding of spatially separated but temporally correlated neural events, which results in a unified perceptual experience. The extent of these interactions can be examined by means of a mathematical algorithm called 'coherence', which reflects the 'strength' of functional interactions between cortical areas.

The commissure of the inferior colliculus shapes frequency response areas in rat: an in vivo study using reversible blockade with microinjection of kynurenic acid.

The commissure of the inferior colliculus (CoIC) interconnects corresponding frequency-band laminae in the two inferior colliculi (ICs). Although the CoIC has been studied neurophysiologically in vitro, the effect of the CoIC on the responses of IC neurons to physiological stimuli has not been addressed. In this study, we injected the glutamate receptor blocker kynurenic acid into one IC while recording the frequency response areas (FRAs) of neurons in the other, to test the hypothesis that frequency response properties of IC neurons are influenced by commissural inputs from the contralateral IC.

Inferior colliculus unitary activity in wakefulness, sleep and under barbiturates.

The spontaneous unitary activity and the response to contralateral tone-burst were analyzed in the inferior colliculus (IC) of guinea pigs during the sleep-waking cycle and under the effects of pentobarbital anesthesia. Minor changes were observed in both spontaneous and evoked activity between wakefulness (W) and slow wave sleep (SWS). On the other hand, a consistent increase in the mean spontaneous firing rate and a significant decrement in the signal-to-noise ratio (S/N ratio) was observed during paradoxical sleep (PS).