Epilepsy Seizures in Spontaneously Hypertensive Rats After Acoustic Stimulation: Role of Renin-Angiotensin System

Spontaneously hypertensive rats vs. Wistar Kyoto and Wistar rats: an assessment of anxiety, motor activity, memory performance, and seizure susceptibility

Spontaneously hypertensive rats (SHRs) are widely accepted for modeling essential hypertension and Attention deficit hyperactivity disorder (ADHD). However, data concerning central nervous system changes associated with behavioral responses of this strain and usage of Wistar Kyoto (WKY) rats as controls are confounding. The objective of the present study was to assess the impact of anxiety and motor activity on the cognitive responses of SHRs compared to Wistar and WKY rats. In addition, the role of brain-derived neurotrophic factor (BDNF) in the hippocampus on cognitive behavior and seizure susceptibility in the three strains was evaluated. In Experiment#1, SHR demonstrated impulsive responses in the novelty suppression feeding test accompanied by impaired spatial working and associative memory in the Y maze and object recognition test compared with the Wistar rat but not WKY rats. In addition, the WKY rats exhibited diminished activity compared to Wistar rats in an actimeter. In Experiment#2, the seizure susceptibility was assessed by 3-min electroencephalographic (EEG) recording after two consecutive injections of pentylenetetrazol (PTZ) (20+40 mg/kg). The WKY rats were more vulnerable to rhythmic metrazol activity (RMA) than the Wistar rats. In contrast, Wistar rats were more prone to generalized tonic-clonic seizures (GTCS) than WKY rats and SHRs. Control SHR had lower BDNF expression in the hippocampus compared to Wistar rats. However, while the BDNF levels were elevated in the Wistar and WKY rats after PTZ injection, no change in this signaling molecule was observed in the SHR in the seizure condition. The results suggest Wistar rats as a more appropriate control of SHR than WKY rats for studying memory responses mediated by BDNF in the hippocampus. The higher vulnerability to seizures in Wistar and WKY rats compared to SHR might be linked to PTZ-induced decreased expression of BDNF in the hippocampus.

Impaired Local and Long-Range Brain Connectivity and Visual Response in a Genetic Rat Model of Hyperactivity Revealed by Functional Ultrasound

Attention-Deficit hyperactivity disorder (ADHD) is a central nervous system (CNS) disorder frequently associated with other psychiatric disorders. Pathophysiology processes at stake in ADHD are still under investigation and interestingly neuroimaging data points to modulated brain connectivity in patients. The genetic spontaneously hypertensive rat (SHR) model has been widely used to study pathophysiological underpinnings of ADHD and resting-state brain connectivity using functional magnetic resonance imaging. Here, functional ultrasound imaging, a new technique enabling fast measurement of cerebral blood volume (CBV), was used to further characterize resting-state functional connectivity – at both local and long-range – and visual response in SHR. We demonstrated that response to visual stimulation was increased in SHR in the visual cortex and the superior colliculus. They displayed altered long-range functional connectivity between spatially distinct regions. SHR also displayed modulated local connectivity, with strong increases of regional homogeneity in parts of the motor and visual cortex, along with decreases in the secondary cingulate cortex, the superior colliculus and the pretectal area. As CBV is intricately coupled to cerebral activity, these results suggest an abnormal neural activity in the SHR animal model, consistent with previous clinical studies and demonstrate the potential of functional ultrasound imaging as a translational tool in ADHD.

Blood pressure, body mass index lowering and ketogenesis in Qigong Bigu

Background

Hypertension is one of the most common comorbid conditions of epilepsy. Hypertension and epilepsy may be related to each other. Qigong Bigu practice induces a similar effect as fasting in the first week. As ketogenesis is induced during ketogenic diet therapy, we hypothesize that ketogenesis is detectable and related body weight loss would occur during the first week of Qigong Bigu practice.

Methods

During the prospective observational study, 34 healthy adult participants attended the Qigong Bigu practice for one week. The blood pressure, body weight, calorie consumption, blood glucose and beta-hydroxybutyrate level were measured.

Results

The body weight and body mass index decreased by 2.39 ± 1.34 kg (95%CI 1.92–2.85) and 0.94 ± 0.57 (95%CI 0.73–1.15), respectively, after five days of practice (P < 0.001). The systolic and diastolic blood pressure decreased by 17.86 ± 14.17 mmHg (95%CI 12.36–23.35) and 9.75 ± 7.45 mmHg (95%CI 6.86–12.64), respectively (P < 0.001). The average five-day calorie consumption was 1197.47 ± 569.97 kcal (95%CI 998.60–1396.35). Meanwhile, no symptomatic hypoglycemia or other significant side effects were observed. The blood beta-hydroxybutyrate level increased to a nutritional level of 1.15 ± 1.12 mmol/L (95%CI 0.76–1.62). The calorie consumption negatively correlated to the beta-hydroxybutyrate level in the blood. The loss of body weight and the decrease of body mass index were positively correlated to the blood beta-hydroxybutyrate level.

Conclusions

Qigong Bigu can decrease the blood pressure, the body weight and the body mass index in healthy adult participants. The fasting stage of Qigong Bigu is accompanied by ketogenesis. Clinical trial of Qigong Bigu in hypertension and epilepsy patients might be worthwhile. The blood beta-hydroxybutyrate might be used as a biomarker to evaluate the effect of Qigong Bigu practice during fasting.

Trial registration

ChiCTR1800016923.