Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA A receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.

The selective antihypertensive and stress inhibitory effects of allopregnanolone in BPH/2J mice suggest that allosteric modulation of GABAA receptors, in amygdalo-hypothalamic pathways, may contribute to the development of hypertension in this model and may offer a potential new therapeutic avenue.

13Sequencing-based studies have identified novel risk genes for rare, severe epilepsies and 14 revealed a role of rare deleterious variation in common epilepsies. To identify the shared and 15 distinct ultra-rare genetic risk factors for rare and common epilepsies, we performed a whole- 16 exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,364 controls of 17 European ancestry. We focused on three phenotypic groups; the rare but severe developmental 18 and epileptic encephalopathies (DEE), and the commoner phenotypes of genetic generalized 19 epilepsy (GGE) and non-acquired focal epilepsy (NAFE). We observed that compared to controls, 20 individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in 21 constrained genes and in genes previously associated with epilepsy, with the strongest 22 enrichment seen in DEE and the least in NAFE. Moreover, we found that inhibitory GABAA 23 receptor genes were enriched for missense variants across all three classes of epilepsy, while no 24 enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic 25 pathway or cation channels also showed a significant mutational burden in DEE and GGE. 26 Although no single gene surpassed exome-wide significance among individuals with GGE or 27 NAFE, highly constrained genes and genes encoding ion channels were among the top 28 associations, including CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and 29 GABRG2 for NAFE. Our study confirms a convergence in the genetics of common and rare 30 epilepsies associated with ultra-rare coding variation and highlights a ubiquitous role for 31 GABAergic inhibition in epilepsy etiology in the largest epilepsy WES study to date. 32 33 Epilepsy is a group of disorders characterized by repeated seizures due to excessive electrical 34 activity in the brain, one of the most common and burdensome neurological conditions worldwide 1; 35 2 . A core challenge for epilepsy genetics is identifying and disentangling the genetic architecture 36 and biological mechanisms underlying the variety of epilepsy types (e.g., focal vs. generalized) 37 and electroclinical syndromes. While the occurrence of epilepsy for many affected individuals 38 carries an underlying genetic component 3-5 , the highly heterogeneous nature of epileptic seizures, 39 epilepsy types, severity, and comorbidity makes it difficult to determine the specific genetic risks 40 for each patient. For individuals with common, complex types of epilepsy, where inheritance may 41 be due to strongly acting mutations, oligogenic or polygenic, the discovery of genetic risk factors 42 is particularly challenging. 43 Considerable progress in our understanding of the genetic risk factors for epilepsy has 44 been made in recent years thanks to the rapid growth and advancement in sequencing technology. 45 Dozens of epilepsy-causing genes have been identified in individuals diagnosed with severe 46 epilepsy syndromes 6-10 , known as the developmental and ...

Background Writing and digital storage have largely replaced organic memory for encoding and retrieval of information in the modern era, with a corresponding decrease in emphasis on memorization in Western education. In health professional training, however, there remains a large corpus of information for which memorization is the most efficient means of ensuring: A) that the trainee has the required information readily available; and B) that a foundation of knowledge is laid, upon which the medical trainee builds multiple, complex layers of detailed information during advanced training. The carefully staged progression in early- to late- years’ medical training from broad concepts (e.g. gross anatomy and pharmacology) to in-depth, specialised disciplinary knowledge (e.g. surgical interventions and follow-on care post-operatively) has clear parallels to the progression of training and knowledge exposure that Australian Aboriginal youths undergo in their progression from childhood to adulthood to Tribal Elders. Methods As part of the Rural Health curriculum and the undergraduate Nutrition and Dietetics program in the Monash University Faculty of Medicine, Nursing, and Health Sciences, we tested Australian Aboriginal techniques of memorization for acquisition and recall of novel word lists by first-year medical students (N = 76). We also examined undergraduate student evaluations (N = 49) of the use of the Australian Aboriginal memory technique for classroom study of foundational biomedical knowledge (the tricarboxylic acid cycle) using qualitative and quantitative analytic methods drawing from Bloom’s taxonomy for orders of thinking and learning. Acquisition and recall of word lists were assessed without memory training, or after training in either the memory palace technique or the Australian Aboriginal narrative technique. Results Both types of memory training improved the number of correctly recalled items and reduced the frequency of specific error types relative to untrained performance. The Australian Aboriginal method resulted in approximately a 3-fold greater probability of improvement to accurate recall of the entire word list (odds ratio = 2.82; 95% c.i. = 1.15–6.90), vs. the memory palace technique (odds ratio = 2.03; 95% c.i. = 0.81–5.06) or no training (odds ratio = 1.5; 95% c.i. = 0.54–4.59) among students who did not correctly recall all list items at baseline. Student responses to learning the Australian Aboriginal memory technique in the context of biomedical science education were overwhelmingly favourable, and students found both the training and the technique enjoyable, interesting, and more useful than rote memorization. Our data indicate that this method has genuine utility and efficacy for study of biomedical sciences and in the foundation years of medical training.

Hypertensive Schlager mice (BPH/2J) have neurogenic hypertension associated with abnormal reactivity of neurons in the forebrain integrating the response to aversive stress. We found that they also have functional and molecular differences in GABAA receptors compared to their normotensive counterparts (BPN/3J). Allopregnanolone is an endogenous neurosteroid reduced by chronic stress and when administered, decreases anxiety by positive allosteric modulation of GABAA receptors. We therefore compared the effect of chronic intracerebroventricular allopregnanolone and its vehicle on blood pressure and stress reactivity in BPH/2J and BPH/3J mice. Implantation of telemetric probes enabled continuous recordings of blood pressure (BP) at rest and during aversive stressors (restraint and dirty cage switch stress). Two weeks of allopregnanolone reduced MAP (‐9.8±4.3mmHg) and the depressor response to ganglionic blockade (‐10.5mmHg) in BPH/2J but had little effect in BPN/3J. Furthermore, allopregnanolone selectively reduced the pressor response to restraint stress by 27.4% in BPH/2J mice. The selective antihypertensive and stress inhibitory effects of allopregnanolone in BPH/2J mice suggests that allosteric modulation of GABAA receptors has therapeutic potential to treat stress related hypertension.