Influence of Physical Activity on Human Sensory Long-Term Potentiation.

A growing body of literature has explored the influence of physical activity on brain structure and function. While the mechanisms of this relationship remain largely speculative, recent research suggests that one of the effects of physical exercise is an increase in synaptic long-term potentiation (LTP). This has not yet been explored directly in humans due to the difficulty of measuring LTP non-invasively. However, we have previously established that LTP-like changes in visual-evoked potentials (VEPs) can be measured in humans. Here, we investigated whether physical fitness status affects the degree of visual sensory LTP. Using a self-report measure of physical activity, participants were split into two groups: a high-activity group, and a low-activity group. LTP was measured and compared between the two groups using the previously established electroencephalography-LTP paradigm, which assesses the degree to which the N1b component of the VEP elicited by a sine grating is potentiated (enhanced) following a rapid "tetanic" presentation of that grating. Both groups demonstrated increased negativity in the amplitude of the N1b component of the VEP immediately after presentation of the visual "tetanus," indicating potentiation. However, after a 30-min rest period, the N1b for the high-activity group remained potentiated while the N1b for the low-activity group returned to baseline. This study presents the first evidence for the impact of self-reported levels of physical activity on LTP in humans, and sheds light on potential neurological mechanisms underlying the relationship between physical fitness and cognition.

Improving surgical training: Establishing a surgical anatomy programme in Scotland.

BACKGROUND: It is well recognized that a sound foundation in surgical anatomy is a cornerstone of safe surgical practice, yet many trainees struggle with the upskilling in anatomy that is required to support their day-to-day practice. In the context of the UK-wide Improving Surgical Training pilot, we set out to establish a surgical anatomy programme for core surgical trainees in the Scotland Deanery. The aim was to enable all trainees to review the surgical anatomy of the whole body to MRCS level at least once during core surgical training. MATERIALS AND METHODS: Teaching was delivered in Edinburgh, with trainees commuting from all parts of the Scotland Deanery. Individual teaching days focused on the surgical anatomy of the head and neck, trunk and limbs, using a combination of lectures (principles and cases) and interactive demonstrations on prosected specimens. Faculty comprised a balance of surgical demonstrators and senior academic staff, including MRCS examiners. RESULTS: In total, 16 individual teaching sessions were attended by over 300 trainees across the first 2 years of the programme. Evaluation form response rate was nearly 80%. The programme was highly rated by trainees in relation to the method of delivery, level of teaching and surgical focus. CONCLUSION: Surgical anatomy remains an integral part of surgical training. Our experience in developing a deanery-wide surgical anatomy programme highlights the crucial links between medical school, training deanery and surgical college. This collaborative approach can be extended to higher surgical training and continuing professional development, and the methods can be adapted to meet the needs of trainees in different parts of the globe.

Bilateral submandibular gland nodular oncocytic hyperplasia with papillary cystadenoma-like areas.

A 57-year-old man presented in 2016 with a 4-month history of a right submandibular mass, having undergone left submandibular gland (SMG) excision in 2003. Imaging suggested a benign tumour and subsequent core biopsy findings suggested a nodular oncocytic hyperplasia, similar to the tumour removed from the contralateral side. This was confirmed on histological analysis following right submandibular gland excision which showed characteristic features of nodular oncocytic hyperplasia along with an unusual diffuse papillary cystadenoma-like ductal proliferation, similar to that seen in the 2003 specimen. A diagnosis of multinodular adenomatous oncocytic hyperplasia (MAOH) was rendered in order to communicate the unique histological features that have otherwise not been described in the literature. We believe that this is the first reported case of non-synchronous multinodular oncocytic hyperplasia and the first case affecting the submandibular glands.

The brain-derived neurotrophic factor (BDNF) val66met polymorphism differentially affects performance on subscales of the Wechsler Memory Scale - Third Edition (WMS-III).

Single nucleotide polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and the catechol-O-methyltransferase (COMT) gene influence brain structure and function, as well as cognitive abilities. They are most influential in the hippocampus and prefrontal cortex (PFC), respectively. Recall and recognition are forms of memory proposed to have different neural substrates, with recall having a greater dependence on the PFC and hippocampus. This study aimed to determine whether the BDNF val(66)met or COMT val(158)met polymorphisms differentially affect recall and recognition, and whether these polymorphisms interact. A sample of 100 healthy adults was assessed on recall and familiarity-based recognition using the Faces and Family Pictures subscales of the Wechsler Memory Scale - Third Edition (WMS-III). COMT genotype did not affect performance on either task. The BDNF polymorphism (i.e., met carriers relative to val homozygotes) was associated with poorer recall ability, while not influencing recognition. Combining subscale scores in memory tests such as the WMS might obscure gene effects. Our results demonstrate the importance of distinguishing between recall and familiarity-based recognition in neurogenetics research.

Brain-derived neurotrophic factor Val66Met polymorphism, human memory, and synaptic neuroplasticity.

Some people have much better memory than others, and there is compelling evidence that a considerable proportion of this variation in memory ability is genetically inherited. A form of synaptic plasticity known as long-term potentiation (LTP) is the principal candidate mechanism underlying memory formation in neural circuits, and it might be expected, therefore, that a genetic influence on the degree of LTP might in turn influence memory abilities. Of the genetic variations thought to significantly influence mnemonic ability in humans, the most likely to have its effect via LTP is a single nucleotide polymorphism affecting brain-derived neurotrophic factor [BDNF (Val66Met)]. However, although it is likely that BDNF influences memory via a modulation of acute plasticity (i.e., LTP), BDNF also has considerable influence on structural development of neural systems. Thus, the influence of BDNF (Val66Met) on mnemonic performance via influences of brain structure as well as function must also be considered. In this brief review, we will describe the phenomenon of LTP and its study in non-human animals. We will discuss the relatively recent attempts to translate this work to studies in humans. We will describe how this has enabled investigation of the effect of the BDNF polymorphism on LTP, on brain structure, and on memory performance.