Mild repetitive head injury is a serious health problem with long-term negative consequences. Changes in brain neurobiology were assessed with MRI in a model of head injury designed to reflect the human experience. Rats were maintained on a reverse light-dark cycle and head impacted daily at 24 h intervals over three days while fully awake under red light illumination. There was no neuroradiological evidence of brain damage. Rats were imaged for changes in blood brain barrier permeability, edema and gray matter microarchitecture, and resting state functional connectivity. Data were registered to a 3D MRI rat atlas with 173 segmented brain areas providing site-specific information on each imaging modality. Changes in BBB permeability were minimal and localized to the hippocampus and cerebellum. There was evidence of cytotoxic edema in the basal ganglia, thalamus, and cerebellum. There was a global decrease in connectivity and an increase in gliosis in the thalamus, cerebellum, and hippocampus. This study shows a sequelae of neuropathology caused by mild repetitive head injury that is commonly observed in clinical practice using MRI in patients. As such, it may serve as a model for testing the efficacy of new therapeutics using any or all of the measures as biomarkers to assess drug efficacy.
Animals ; Magnetic Resonance Imaging/methods* ; Disease Models, Animal ; Brain/physiopathology* ; Male ; Rats ; Rats, Sprague-Dawley ; Blood-Brain Barrier/diagnostic imaging* ; Multimodal Imaging ; Wakefulness/physiology* ; Craniocerebral Trauma/physiopathology*

OBJECTIVE: To determine whether the glutamatergic neurons in the paraventricular nucleus of the thalamus (PVT) is involved in the change of consciousness induced by propofol through a combination of behavioral and electroencephalography (EEG) recordings. METHODS: Healthy male VGluT2-IRES-Cre mice aged 8-12 weeks were used in this experiment. (1) The glutamatergic neurons in the PVT was selectively damaged, and its effect on propofol anesthesia induction and recovery times as well as the energy of EEG in different frequency bands were observed. (2) Optogenetics was utilized to selectively activate or inhibit glutamatergic neurons in the PVT to assess their influence on anesthesia induction and recovery times under propofol as well as the energy of EEG in different frequency bands. RESULTS: (1) Selective ablation of glutamatergic neurons in the PVT significantly delayed recovery from propofol anesthesia with statistical difference as compared with the control group (s: 409.43±117.49 vs. 273.71±51.52, P < 0.05), but had no significant effect on anesthesia induction time. During the recovery phase of propofol, selective ablation of glutamatergic neurons in the PVT exhibited higher α-wave (1-4 Hz) power and reduced β-wave (12-15 Hz) power as compared with the control group. (2) Optogenetic activation of glutamatergic neurons in the PVT significantly prolonged anesthesia induction time under propofol (s: 161.67±29.09 vs. 119.33±18.98, P < 0.05) while significantly shortening the recovery time from propofol anesthesia (s: 208.67±57.19 vs. 288.83±34.52, P < 0.05). During the induction phase of propofol, activation of glutamatergic neurons in PVT reduced α-wave and α-wave (8-12 Hz) power, while during the recovery phase, α-wave power significantly increased as compared with the control group. (3) Optogenetic inhibition of glutamatergic neurons in the PVT delayed recovery from propofol anesthesia (s: 403.50±129.06 vs. 252.83±45.31, P < 0.05), but had no significant effect on induction time. During both the induction phase and recovery phase of propofol, the optogenetic inhibition of glutamatergic neurons in the PVT exhibited increased α-wave power. CONCLUSION Glutamatergic neurons in the PVT are involved in the regulation of propofol anesthesia recovery process.
Animals ; Propofol/pharmacology* ; Mice ; Neurons/physiology* ; Male ; Electroencephalography ; Wakefulness ; Midline Thalamic Nuclei ; Optogenetics

The nucleus accumbens (NAc) plays an important role in various emotional and motivational behaviors that rely on heightened wakefulness. However, the neural mechanisms underlying the relationship between arousal and emotion regulation in NAc remain unclear. Here, we investigated the roles of a specific subset of inhibitory corticotropin-releasing hormone neurons in the NAc (NAc^CRH) in regulating arousal and emotional behaviors in mice. We found an increased activity of NAc^CRH neurons during wakefulness and rewarding stimulation. Activation of NAc^CRH neurons converts NREM or REM sleep to wakefulness, while inhibition of these neurons attenuates wakefulness. Remarkably, activation of NAc^CRH neurons induces a place preference response (PPR) and decreased basal anxiety level, whereas their inactivation induces a place aversion response and anxious state. NAc^CRH neurons are identified as the major NAc projection neurons to the bed nucleus of the stria terminalis (BNST). Furthermore, activation of the NAc^CRH-BNST pathway similarly induced wakefulness and positive emotional behaviors. Taken together, we identified a basal forebrain CRH pathway that promotes the arousal associated with positive affective states.
Animals ; Septal Nuclei/metabolism* ; Nucleus Accumbens/physiology* ; Corticotropin-Releasing Hormone/metabolism* ; Wakefulness/physiology* ; Neurons/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; Neural Pathways/physiology* ; Anxiety/physiopathology* ; Reward

This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.
Rats ; Mice ; Animals ; Wakefulness ; Auditory Pathways/physiology* ; Rats, Wistar ; Mice, Inbred C57BL ; Thalamus/physiology*

The parabrachial nucleus (PBN) integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing, emotion, and sleep/wake regulation through the neural circuits that connect to the forebrain and the brainstem. However, the precise identity and function of distinct PBN subpopulations are still largely unknown. Here, we leveraged molecular characterization, retrograde tracing, optogenetics, chemogenetics, and electrocortical recording approaches to identify a small subpopulation of neurotensin-expressing neurons in the PBN that largely project to the emotional control regions in the forebrain, rather than the medulla. Their activation induces freezing and anxiety-like behaviors, which in turn result in tachypnea. In addition, optogenetic and chemogenetic manipulations of these neurons revealed their function in promoting wakefulness and maintaining sleep architecture. We propose that these neurons comprise a PBN subpopulation with specific gene expression, connectivity, and function, which play essential roles in behavioral and physiological regulation.
Parabrachial Nucleus/physiology* ; Wakefulness/physiology* ; Neurons/physiology* ; Emotions ; Sleep

Objective: To explore the developmental characteristics of circadian rhythms in hypothalamus-pituitary-adrenal (HPA) axis during puberty. Methods: A total of 1 070 students from Grade 2-3 in 3 primary schools in Ma'anshan city, Anhui province, were selected for physical examination and circadian rhythm of HPA axis checked from 2015 to 2017. Saliva samples were collected at each of the following three time points: immediately upon wakening, 30 minutes after wakening and bedtime, with the index of circadian rhythm of HPA axis calculated, which including cortisol awake response (CAR), cortisol in puberty priming and diurnal cortisol slope (DCS). Testicular volume, palpation and visual inspection of breast development were used to assess the state of purbety development on boys and girls. Information on gender, date of birth, time to fall asleep, wake-up time and weekly physical activity were gathered through questionnaire survey. Non-parametric test was used to compare the differences of baseline, follow-up period and different adolescent developmental processes of each index on circadian rhythm of HPA axis. Results: During the period of follow-up program and comparing with the continuous undeveloped group, CAR and the changes of CAR showed significantly increase, both in the puberty priming group and continuous development group, with statistically significant differences (CAR: Z=8.551, 4.680, respectively; P<0.01; the changes of CAR: Z=4.079, 2.700, respectively, P<0.01). There were no significant differences noticed in CAR and the changes of CAR between puberty priming group or continuous development group. The area under the curve (AUC) of cortisol in puberty priming group was slightly higher than that in the persistent undeveloped group (Z=2.591, P=0.010). Both the changes of daily cortisol slope (DCS) in puberty priming group and continuing developed group decreased significantly, when comparing with those in continuous undeveloped group (Z=-2.450, Z=-2.151; all P<0.05). There was no significant difference noticed in the changes of cortisol in puberty priming and DCS between different puberty development stages (the changes of AUC: χ(2)=2.747, P=0.253; DCS: χ(2)=4.554, P=0.032). Conclusions: The indexes of circadian rhythm of HPA axis were associated with the development of puberty. Both the cortisol awakening response and the total amount of diurnal cortisol secretion showed an increase, along with the puberty development. The change of diurnal cortisol slope declined with the development of puberty.
Adolescent ; Area Under Curve ; Circadian Rhythm ; Female ; Humans ; Hydrocortisone ; Hypothalamo-Hypophyseal System ; Male ; Pituitary-Adrenal System ; Pregnancy ; Saliva ; Sexual Maturation/physiology* ; Surveys and Questionnaires ; Wakefulness

OBJECTIVETo assess the biological effects of the six-herb mixture Anti-Insomia Formula (AIF) extract using caffeine-induced insomnia Drosophila model and short-sleep mutants.

METHODSCaffeineinduced insomnia wild-type Drosophila and short-sleep mutant flies minisleep (mns) and Hyperkinetic(Y) (Hk(Y)) were used to assess the hypnotic effects of the AIF in vivo. The night time activity, the amount of night time sleep and the number of sleep bouts were determined using Drosophila activity monitoring system. Sleep was defined as any period of uninterrupted behavioral immobility (0 count per minute) lasting > 5 min. Night time sleep was calculated by summing up the sleep time in the dark period. Number of sleep bouts was calculated by counting the number of sleep episodes in the dark period.

RESULTSAIF at the dosage of 50 mg/mL, effectively attenuated caffeine-induced wakefulness (P<0.01) in wild-type Canton-S flies as indicated by the reduction of the sleep bouts, night time activities and increase of the amount of night time sleep. AIF also significantly reduced sleeping time of short-sleep Hk(Y) mutant flies (P<0.01). However, AIF did not produce similar effect in mns mutants.

CONCLUSIONAIF might be able to rescue the abnormal condition caused by mutated modulatory subunit of the tetrameric potassium channel, but not rescuing the abnormal nerve firing caused by Shaker gene mutation. This study provides the scientific evidence to support the use of AIF in Chinese medicine for promoting sleep quality in insomnia.

Animals ; Caffeine ; Chromatography, High Pressure Liquid ; Disease Models, Animal ; Drosophila melanogaster ; drug effects ; physiology ; Hypnotics and Sedatives ; pharmacology ; therapeutic use ; Mutation ; genetics ; Potassium Channels ; genetics ; Sleep ; drug effects ; Sleep Initiation and Maintenance Disorders ; drug therapy ; Wakefulness ; drug effects

Urodynamic investigation in conscious rats is widely employed to explore functional bladder disorders of various etiologies and pathogeneses. Rats can be placed in restraining cages or wide cabinets where they are allowed to move freely during cystometry. However, the requirements of special devices hampered the application of urodynamic test in freely moving rats, and whether the restraint has any effects on urodynamic parameters in conscious rats remains obscure. In the present study, we described a novel approach for urodynamic investigation in both restrained and freely moving conscious rats. In addition, we for the first time systematically compared the urodynamic parameters of rats in the two conditions. With the current method, we successfully recorded stable and repeatable intravesical pressure traces and collected expected reliable data, which supported the idea that the restraint does not affect the activity of the micturition reflex in rats, provided sufficient and appropriate measures could be applied during cystometry. Fewer technique problems were encountered during urodynamic examination in restrained rats than in freely moving ones. Taken together, conscious cystometry in rats placed in restraining cages with proper managements is a reliable and practical approach for evaluating the detrusor activity and bladder function.
Animals ; Diagnostic Techniques, Urological ; instrumentation ; Female ; Movement ; Rats ; Rats, Sprague-Dawley ; Reflex ; Restraint, Physical ; Urinary Bladder ; physiology ; Urodynamics ; Wakefulness

BACKGROUNDSleep/wake disturbances in patients with amyotrophic lateral sclerosis (ALS) are well-documented, however, no animal or mechanistic studies on these disturbances exist. Orexin is a crucial neurotransmitter in promoting wakefulness in sleep/wake regulation, and may play an important role in sleep disturbances in ALS. In this study, we used SOD1-G93A transgenic mice as an ALS mouse model to investigate the sleep/wake disturbances and their possible mechanisms in ALS.

METHODSElectroencephalogram/electromyogram recordings were performed in SOD1-G93A transgenic mice and their littermate control mice at the ages of 90 and 120 days, and the samples obtained from these groups were subjected to quantitative reverse transcriptase-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay.

RESULTSFor the first time in SOD1-G93A transgenic mice, we observed significantly increased wakefulness, reduced sleep time, and up-regulated orexins (prepro-orexin, orexin A and B) at both 90 and 120 days. Correlation analysis confirmed moderate to high correlations between sleep/wake time (total sleep time, wakefulness time, rapid eye movement [REM] sleep time, non-REM sleep time, and deep sleep time) and increase in orexins (prepro-orexin, orexin A and B).

CONCLUSIONSleep/wake disturbances occur before disease onset in this ALS mouse model. Increased orexins may promote wakefulness and result in these disturbances before and after disease onset, thus making them potential therapeutic targets for amelioration of sleep disturbances in ALS. Further studies are required to elucidate the underlying mechanisms in the future.

Amyotrophic Lateral Sclerosis ; genetics ; metabolism ; Animals ; Female ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Mice ; Mice, Transgenic ; Neuropeptides ; genetics ; metabolism ; Orexins ; Reverse Transcriptase Polymerase Chain Reaction ; Sleep ; physiology ; Superoxide Dismutase ; genetics ; metabolism ; Superoxide Dismutase-1 ; Wakefulness ; physiology

gamma-Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is involved in sleep physiology. Caffeine is widely used psychoactive substance known to induce wakefulness and insomnia to its consumers. This study was performed to examine whether GABA extracts from fermented rice germ ameliorates caffeine-induced sleep disturbance in mice, without affecting spontaneous locomotor activity and motor coordination. Indeed, caffeine (10 mg/kg, i.p.) delayed sleep onset and reduced sleep duration of mice. Conversely, rice germ ferment extracts-GABA treatment (10, 30, or 100 mg/kg, p.o.), especially at 100 mg/kg, normalized the sleep disturbance induced by caffeine. In locomotor tests, rice germ ferment extracts-GABA slightly but not significantly reduced the caffeine-induced increase in locomotor activity without affecting motor coordination. Additionally, rice germ ferment extracts-GABA per se did not affect the spontaneous locomotor activity and motor coordination of mice. In conclusion, rice germ ferment extracts-GABA supplementation can counter the sleep disturbance induced by caffeine, without affecting the general locomotor activities of mice.
Animals ; Anxiety ; Caffeine ; Central Nervous System ; gamma-Aminobutyric Acid* ; Mice* ; Motor Activity ; Neurotransmitter Agents ; Physiology ; Sleep Initiation and Maintenance Disorders ; Wakefulness