Normal ageing and the brain

1998 ◽  
Vol 15 (1) ◽  
pp. 26-28
Author(s):  
CS Breathnach

AbstractInterest in the psychiatric aspects of old age predated the institution of geriatrics as a clinical discipline, but the systematic study of the ageing brain only began in the second half of this century when an ageing population presented a global numerical challenge to society. In the senescent cerebral cortex, though the number of neurons is not reduced, cell shrinkage results in synaptic impoverishment with consequent cognitive impairment. Recent advances in imaging techniques, combined with burgeoning knowledge of neurobiological structure and function, have increased our understanding of the ageing processes in the human brain and permit an optimistic approach in the application of the newer insights into neuropsychology and geriatric psychiatry.

2015 ◽  
Vol 21 (4) ◽  
pp. 251-260 ◽  
Author(s):  
Cristina Martinelli ◽  
Sukhwinder S. Shergill

SummaryRecent years have seen a dramatic increase in the advances and applications of medical imaging techniques. Tools with familiar acronyms such as MRI, EEG/MEG and PET/SPECT have provided invaluable information not only about the brain structure and function associated with psychiatric disorders, but increasingly about the mechanisms underpinning these disorders. This evolving understanding of the specific pathophysiology of mental disorder paves the way for improvement in the diagnosis, treatment and prognosis of the disorders managed in everyday clinical practice. This article gives an overview of the main neuroimaging approaches, contemporary applications of this technology to psychiatric disorder and signposts to the exciting possibilities for the future.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110311
Author(s):  
Can Zhao ◽  
Shu-Sheng Bao ◽  
Meng Xu ◽  
Jia-Sheng Rao

Spinal cord injury (SCI) destroys the sensorimotor pathway and blocks the information flow between the peripheral nerve and the brain, resulting in autonomic function loss. Numerous studies have explored the effects of obstructed information flow on brain structure and function and proved the extensive plasticity of the brain after SCI. Great progress has also been achieved in therapeutic strategies for SCI to restore the “re-innervation” of the cerebral cortex to the limbs to some extent. Although no thorough research has been conducted, the changes of brain structure and function caused by “re-domination” have been reported. This article is a review of the recent research progress on local structure, functional changes, and circuit reorganization of the cerebral cortex after SCI. Alterations of structure and electrical activity characteristics of brain neurons, features of brain functional reorganization, and regulation of brain functions by reconfigured information flow were also explored. The integration of brain function is the basis for the human body to exercise complex/fine movements and is intricately and widely regulated by information flow. Hence, its changes after SCI and treatments should be considered.


1997 ◽  
Vol 352 (1362) ◽  
pp. 1703-1709 ◽  
Author(s):  
◽  
Marilyn S. Albert

With advancing age, the majority of individuals experience declines in their ability to learn and remember. An examination of brain structure and function in healthy older persons across the age range indicates that there are substantial changes in the brain that appear to be related to alterations in memory. The nature of the cognitive and neurobiological alterations associated with age-related change is substantially different from that seen in the early stages of a dementing illness, such as Alzheimer's disease. These differences have implications for potential intervention strategies.


2006 ◽  
Vol 34 (5) ◽  
pp. 863-867 ◽  
Author(s):  
S. Mizielinska ◽  
S. Greenwood ◽  
C.N. Connolly

Maintaining the correct balance in neuronal activation is of paramount importance to normal brain function. Imbalances due to changes in excitation or inhibition can lead to a variety of disorders ranging from the clinically extreme (e.g. epilepsy) to the more subtle (e.g. anxiety). In the brain, the most common inhibitory synapses are regulated by GABAA (γ-aminobutyric acid type A) receptors, a role commensurate with their importance as therapeutic targets. Remarkably, we still know relatively little about GABAA receptor biogenesis. Receptors are constructed as pentameric ion channels, with α and β subunits being the minimal requirement, and the incorporation of a γ subunit being necessary for benzodiazepine modulation and synaptic targeting. Insights have been provided by the discovery of several specific assembly signals within different GABAA receptor subunits. Moreover, a number of recent studies on GABAA receptor mutations associated with epilepsy have further enhanced our understanding of GABAA receptor biogenesis, structure and function.


2021 ◽  
pp. 2100137
Author(s):  
Jeroen L.M. van Doorn ◽  
Francesca Pennati ◽  
Hendrik H.G. Hansen ◽  
Baziel G.M. van Engelen ◽  
Andrea Aliverti ◽  
...  

Respiratory muscle weakness is common in neuromuscular disorders and leads to significant respiratory difficulties. Therefore, reliable and easy assessment of respiratory muscle structure and function in neuromuscular disorders is crucial. In the last decade, ultrasound and MRI emerged as promising imaging techniques to assess respiratory muscle structure and function. Respiratory muscle imaging directly measures the respiratory muscles and, in contrast to pulmonary function testing, is independent of patient effort. This makes respiratory muscle imaging suitable to use as tool in clinical respiratory management and as outcome parameter in upcoming drug trials for neuromuscular disorders, particularly in children. In this narrative review, we discuss the latest studies and technological developments in imaging of the respiratory muscles by US and MR, and its clinical application and limitations. We aim to increase understanding of respiratory muscle imaging and facilitate its use as outcome measure in daily practice and clinical trials.


2010 ◽  
Vol 5 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Denise C. Park ◽  
Chih-Mao Huang

There is clear evidence that sustained experiences may affect both brain structure and function. Thus, it is quite reasonable to posit that sustained exposure to a set of cultural experiences and behavioral practices will affect neural structure and function. The burgeoning field of cultural psychology has often demonstrated the subtle differences in the way individuals process information—differences that appear to be a product of cultural experiences. We review evidence that the collectivistic and individualistic biases of East Asian and Western cultures, respectively, affect neural structure and function. We conclude that there is limited evidence that cultural experiences affect brain structure and considerably more evidence that neural function is affected by culture, particularly activations in ventral visual cortex—areas associated with perceptual processing.


Author(s):  
Steven E. Hyman ◽  
Doug McConnell

‘Mental illness: the collision of meaning with mechanism’ is based on the views of psychiatry that Steven Hyman articulated in his Loebel Lectures—mental illness results from the disordered functioning of the human brain and effective treatment repairs or mitigates those malfunctions. This view is not intended as reductionist as causes of mental illness and contributions to their repair may come from any source that affects the structure and function of the brain. These might include social interactions and other sources of lived experience, ideas (such as those learned in cognitive therapy), gene sequences and gene regulation, metabolic factors, drugs, electrodes, and so on. This, however, is not the whole story for psychiatry on Hyman’s view; interpersonal interactions between clinicians and patients, intuitively understood in such folk psychological terms as selfhood, intention, and agency are also critical for successful practice. As human beings who are suffering, patients seek to make sense of their lives and benefit from the empathy, respect, and a sense of being understood not only as the objects of a clinical encounter, but also as subjects. Hyman’s argument, however, is that the mechanisms by which human brains function and malfunction to produce the symptoms and impairments of mental illness are opaque to introspection and that the mechanistic understandings necessary for diagnosis and treatment are incommensurate with intuitive (folk psychological) human self-understanding. Thus, psychiatry does best when skillful clinicians switch between an objectifying medical and neurobiological stance and the interpersonal stance in which the clinician engages the patients as a subject. Attempts to integrate these incommensurate views of patients and their predicaments have historically produced incoherent explanations of psychopathology and have often led treatment astray. For example, privileging of folk psychological testimony, even when filtered through sophisticated theories has historically led psychiatry into intellectually blind and clinically ineffective cul-de-sacs such as psychoanalysis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kanchan Bisht ◽  
Kenneth A. Okojie ◽  
Kaushik Sharma ◽  
Dennis H. Lentferink ◽  
Yu-Yo Sun ◽  
...  

AbstractMicroglia are brain-resident immune cells with a repertoire of functions in the brain. However, the extent of their interactions with the vasculature and potential regulation of vascular physiology has been insufficiently explored. Here, we document interactions between ramified CX3CR1 + myeloid cell somata and brain capillaries. We confirm that these cells are bona fide microglia by molecular, morphological and ultrastructural approaches. Then, we give a detailed spatio-temporal characterization of these capillary-associated microglia (CAMs) comparing them with parenchymal microglia (PCMs) in their morphological activities including during microglial depletion and repopulation. Molecularly, we identify P2RY12 receptors as a regulator of CAM interactions under the control of released purines from pannexin 1 (PANX1) channels. Furthermore, microglial elimination triggered capillary dilation, blood flow increase, and impaired vasodilation that were recapitulated in P2RY12−/− and PANX1−/− mice suggesting purines released through PANX1 channels play important roles in activating microglial P2RY12 receptors to regulate neurovascular structure and function.


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