Effects of extracellular pH reductions on [3H]d-aspartate and [3H]noradrenaline release by presynaptic nerve terminals isolated from rat cerebral cortex

Metabolic regulation of synaptic activity

Brain tissue is bioenergetically expensive. In humans, it composes approximately 2% of body weight and accounts for approximately 20% of calorie consumption. The brain consumes energy mostly for ion and neurotransmitter transport, a process that occurs primarily in synapses. Therefore, synapses are expensive for any living creature who has brain. In many brain diseases, synapses are damaged earlier than neurons start dying. Synapses may be considered as vulnerable sites on a neuron. Ischemic stroke, an acute disturbance of blood flow in the brain, is an example of a metabolic disease that affects synapses. The associated excessive glutamate release, called excitotoxicity, is involved in neuronal death in brain ischemia. Another example of a metabolic disease is hypoglycemia, a complication of diabetes mellitus, which leads to neuronal death and brain dysfunction. However, synapse function can be corrected with “bioenergetic medicine”. In this review, a ketogenic diet is discussed as a curative option. In support of a ketogenic diet, whereby carbohydrates are replaced for fats in daily meals, epileptic seizures can be terminated. In this review, we discuss possible metabolic sensors in synapses. These may include molecules that perceive changes in composition of extracellular space, for instance, ketone body and lactate receptors, or molecules reacting to changes in cytosol, for instance, KATP channels or AMP kinase. Inhibition of endocytosis is believed to be a universal synaptic mechanism of adaptation to metabolic changes.

Premonitory Urges in Patients with Gilles de la Tourette Syndrome: An Italian Translation and a 7-Year Follow-up

OBJECTIVE

Premonitory sensations or urges (PUs) are described as characteristic sensory phenomena preceding tics, which are often described as unpleasant. They occur in 90% of patients affected by Gilles de la Tourette Syndrome (GTS). They may be localized (around the area of tic) or generalized (covering a wide area of the body). The PUs can be measured by the Premonitory Urge for Tics Scale (PUTS). In this study we translated the PUTS scale into Italian and then assessed children and adolescents/young people (CYP) with GTS using the scale.

METHODS

GTS patients were assessed at the initial interview and after 7 years to evaluate the PUs, and the correlations of the PUTS scores with tic severity, severity of comorbid disorders (obsessive-compulsive disorder [OCD], attention-deficit/hyperactivity disorder [ADHD]), and a variety of coexisting psychopathologies.

RESULTS

A total of 95 patients were studied. We successfully translated the PUTS into Italian, and our results indicated that our translated version had good psychometric properties. Results demonstrated that the CYP had PUs at both interviews, but that older CYP were more consistent in reporting PUs than younger CYP (i.e., PUTS scores increased with age). We found no correlations between PUTS score and tic severity at either interview. We found a statistical significant correlation between PUTS score and obsessive-compulsive symptoms (OCS) at both interviews; Moreover both the PUTS and Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) scores increased significantly, whereas the Yale Global Tic Severity Rating Scale (YGTSS) score decreased significantly. We found no relationships between PUTS scores and anxiety, depression, ADHD, and externalizing/internalizing behavioral scores.

CONCLUSIONS

Our results suggest the the Italian translation of the PUTS has good psychometric properties. Although both younger (<10 years of age) and older CYP (≤ 10 years of age) reported PUs, the scores at the initial interview were statistically significantly lower than at follow-up. Moreover, in CYP >10 years of age, the PUs correlated with obsessions and compulsions (CY-BOCS scores).