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A mindfulness relationship-based model to support maternal mental health and the mother-baby relationship in pregnancy and beyond birth
Published in Antonella Sansone, Cultivating Mindfulness to Raise Children Who Thrive, 2020
When there is attunement between two people, creating a sense of safety, Porges (1998) proposes that activation of the myelinated vagus nerve occurs with the softening of facial muscles, relaxation in vocal tone, and opening of the perceptual system to receive input from outside. I assume this state of psychophysiological attunement can be nurtured between mother and prenate (and between mother and father!) to prepare for postnatal bonding. Porges proposes that myelination creates more rapid neural signals transfer, thus more learning, and with the neuroception of safety, the vagus nerve supports the individual becoming open, receptive and approaching others. Myelination is the process of forming a myelin sheath around a nerve to allow nerve impulses to move more quickly. This process of neuroception of safety involves both the mother’s and the infant’s social engagement system and is bidirectional. Porges proposes a social engagement system that “provides a system for voluntary engagement with the environment with special features associated with the prosocial behaviours of communication” (1998, p. 850). The activation of this vagal system may involve the release of the pleasure/love hormone oxytocin and its distribution throughout the body with sensations of positive states associated with physical touching and proximity. In a mother-baby dyad, this corresponds to emotional availability and mutual engagement, indicators of responsiveness and attunement.
Targeting the Nervous System
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
A nerve impulse is a self-propagating wave of electrical disturbance, not current, that travels along the axon membrane of a neurone, due to a temporary reversal of electrical potential difference. This reversal alternates between two states: the resting potential and an action potential. There is a threshold level of stimulus needed to propagate an action potential; this feature is referred to as the ‘all or nothing principle’. The magnitude of a stimulus is perceived by the number of impulses passing in a given time and/or having neurones with different threshold values, which is left for the brain to interpret.
The Psychiatric Body
Published in Roger Cooter, John Pickstone, Medicine in the Twentieth Century, 2020
At the center of brain-behavior studies has been the phenomenon of neurotransmission. Neurotransmitters are chemicals that convey nerve impulses from one neuron to another across the synapse or gap between the neurons. Dopamine, norepinephrine, and serotonin are the chemical messengers that have received the most scientific attention, although by 1995 over 40 such chemical agents had been isolated. The newly reconstituted psychiatric body was formed from the discovery that an excess or shortage of certain chemical-transmitting substances in the central nervous system may effect mood states, including psychotic conditions. Furthermore, identification of particular brain cells and neural systems that secrete particular neurotransmitters has allowed pharmacologists to synthesize chemicals that act directly on the neuronal receptor sites. To test these new compounds, researchers in the clinic and laboratory have turned away from the old case history method that psychodynamic psychiatry relied on. Instead, they have developed a new clinical trial methodology involving intricate statistical analyses and controlled experiments with double-blind, placebo-controlled samples.
Differentiating primary dry eye disease from ocular neuropathic pain: implications for symptom management
Published in Clinical and Experimental Optometry, 2023
Mark T Forristal, Kirk A J Stephenson
The poor correlation of symptoms and clinical signs in ONP accompanied with difficulty in differentiating ONP signs and DED signs leads to challenges in management of this ill-defined disease, and accurate diagnosis is key in terms of guiding patient’s treatment.19 This study aims to describe a 3-part test, which can be used by eyecare practitioners to differentiate DED presentations into DED, ONP and mixed DED/ONP involving the instillation of topical Proxymetacaine and assessment of pain scores. Proxymetacaine acts via reducing the permeability of the neuronal membrane to sodium ions, resulting in the reversible blockage of the initiation and conduction of nerve impulses. As topical anaesthetic drops, such as Proxymetacaine, can be used to provide effective analgesia for corneal incisions during cataract surgery, pain persisting post-Proxymetacaine instillation is unlikely to be of primary corneal/ocular surface origin and is likely of neuropathic source. We hypothesise that patients with neuropathic pain will have less marked reduction in pain scores pre and post-topical Proxymetacaine instillation in comparison with patients with DED. We will also compare the prevalence of presentations of ONP presenting with DED symptoms in hospital ophthalmology settings and in optometric primary care settings.
Syntaphilin mediates axonal growth and synaptic changes through regulation of mitochondrial transport: a potential pharmacological target for neurodegenerative diseases
Published in Journal of Drug Targeting, 2023
Qing-Yun Wu, Hui-Lin Liu, Hai-Yan Wang, Kai-Bin Hu, Ping Liao, Sen Li, Zai-Yun Long, Xiu-Min Lu, Yong-Tang Wang
Physiological activities such as the generation of nerve impulses, the formation of synapses, and the transmission of nerve signalling are all heavily energy-consuming processes. Mitochondria, the organelles found in eukaryotic cells, are responsible for converting stored energy from organic matter into adenosine triphosphate (ATP). They play a critical role in cellular energy metabolism and produce 90% of the ATP required for cellular metabolism [1]. The brain relies heavily on mitochondria to produce most of the ATP needed for its functions and energy metabolism [2], and synapses are the main site of energy expenditure [3]. As the primary energy source for neurons, mitochondria are crucial for maintaining synaptic activities, including synaptic assembly, action potential and synaptic potential production, and synaptic vesicle (SV) transport and recycling [4]. Axonal mitochondrial deficiency affects synaptic transmission, and defective mitochondrial transport and energy deficiency are associated with the failure of axonal regeneration after injury and the pathogenesis of multiple neurological diseases [5–7]. Mitochondrial motility is also affected by stress or damage to its integrity. Consequently, ensuring mitochondrial health and motor function is essential for axonal growth, maintenance of synaptic energy balance, and synaptic function.
Effect of diet supplemented with African Star Apple Fruit Pulp on purinergic, cholinergic and monoaminergic enzymes, TNF-α expression and redox imbalance in the brain of hypertensive rats
Published in Nutritional Neuroscience, 2023
Tosin A. Olasehinde, Seun F. AKomolafe, Iyabo F. Oladapo, Sunday I. Oyeleye
High acetylcholinesterase activity was observed in the brain of hypertensive rats, and this suggests rapid hydrolysis of acetylcholine which may reduce its level in the synaptic cleft, hence disrupting cholinergic metabolism and neurotransmission. Low levels of acetylcholine have been linked with cognitive dysfunction [60]. Acetylcholine is an important neurotransmitter involved in transmitting nerve impulses from one neuron to another [61]. The observed increase in AChE activity also correlates with the significant increase in AChE mRNA expression in the brain of hypertensive rats. These results established that high blood pressure may contribute to cholinergic deficit and impaired cholinergic transmission. After supplementation with FP, acetylcholinesterase activity and AChE mRNA expression was significantly reduced in the brain of hypertensive rats, which suggest inhibition of rapid hydrolysis and depletion of acetylcholine. FP may contain some compounds that may inhibit AChE, hence the observed reduction of the enzyme activity. Compounds such as catechins, epigallocatechin, beta-amyrin acetate and myricetin rhamnoside, previously identified in FP, may induce inhibition of AChE. Previous reports have also indicated that these compounds are potent AChE inhibitors [62–65].