method of the week

Human behavioral assessments in current research of Parkinson’s disease

Parkinson's disease (PD) classifid as a movemtent disorder becasue of complaints about the motor system. Parientes suffer dysfunctions such as resting tremor, rugidity, and postural instability. In recent finds non-motor symtems have been recognized by scientised as early signs of parkinson's disease. These symptomes vary they can manafeste as cognitive impairments, mood dysfunction, hyposmia and pain. Studies have shown that increasing in these symptomes indicate progression in the PD. Scientest are trying to find a behavior test that will sucessfuly evaluate patients symptomes. One scientest intoduced a slection of depression rating scales for used in PD patients, althought there were good rliability restultes the test need to be investegated much deeper becasue that test was not originally disigned for PD patients. Reviews on behavioral test poisnt out that the ideal test should present specific characteristics for example objective and repriducibility, quanification and represebtativesness practicability and sensitivity. Since PD is a very complex syndrome pathophysicologycal characteristics and symptomes are individualized. 




Cannabis and adolescent brain development

 Among adolescents' cannabis use is often related with increased rates of mental illness and constrictive impairment but the neurobiological processes that underlines these statements is still not understood. Epidemiological studies have found that regular cannabis users experience greater rates of psychotic, depression and anxiety symptoms, in contrast to infrequent users.  In this article the study findings from examining acute and chronic effects of cannabis use on the brain are discussed. Focusing on the impact that cannabis has on the adolescence brain. Evidence forms studies done on humans and animals suggests that regular use of cannabis in the adolescent phase is associated with more negative outcomes rather than the usage during adult hood. It is suggested that the adolescent brain is much more vulnerable to the consequences of cannabis exposure. It is possible that the use during adolescence results in disruption in the normative neuromaturation processes because the endocannabinoid system plays such a big role in the brain development. It was identified that the white matter and synaptic pruning development was greatly impacted by the exposure during this young stage of life and potentially altered cognitive and emotional defects. An important factor when testing the effects of cannabis are age, dose, cell type and exposure duration. Although it is helpful to look at the effects cannabis has on animals there are sustain effects that occurs on animals that do not appear in the human brain or systems. In the MRI scan shown in the article it is demonstrated how the brain suffers from 10-12% of brain reduction after being exposed to cannabis for over 10 years, the scan shows that the volume of the left hippocampus was the most effected. There were also documented studies that revealed that prenatal exposure caused volumetric changes in the brain and reduction of cortical grey matter. ffects on the brain?v

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