Neurotransmitter

At the spinal level, the PNS and CNS are bilaterally symmetrical. And studies have shown that the two sides of the spinal cord are not independent due to the findings that unilateral peripheral nociception results in contralateral responses (Koltzeburg, 1999). The contralateral pain was perceived at a lesser magnitude and has a delayed response. This contralateral pain phenomenon can be attributed to a similar pathway as central sensitization leading to secondary hyperalgesia. Primary…

3,4-Methylenedioxymethamphetamine (MDMA), more commonly known as ecstasy, has become a popular recreational drug for adolescents participating in “raves”. Taken as a tablet, MDMA indirectly increases the concentration of serotonin in the central nervous system through the inhibition of monoamine transporters, vesicular monoamine transporters (VMAT) and monoamine oxidase (MAO). Although, MDMA also increases the amount of dopamine and noradrenaline, the excessive release of serotonin is the…

Pain is modulated by descending mechanisms of nociceptive transmission between the brain and spinal cord. Multiple brain regions, pathways, and chemical mediators are involved in this modulation of pain. One type of powerful mediator involved in pain modulation are opioids. Endogenous opioid peptides, as well as exogenous opioid agonists, bind and activate opioid receptors. Activated opioid receptors directly inhibit ON cells and also inhibit GABAergic interneurons which inhibit OFF cells, thus…

ALS is a multi-factorial neurodegenerative disease that affects the upper and lower motor neurons of the spinal cord. It is found in both familial and sporadic forms. Familial ALS is recognized by mutant SOD1 which fails to convert reactive oxygen species to hydrogen peroxide and/or water; however, studies have shown the presence of SOD1 aggregates in sporadic forms as well (Redler and Dokholyan, 2012). This is due to the ability of wild-type SOD1 to become toxic due to oxidative stresses in the…

The primary motor cortex is structure 3, which is located in the back of the frontal lobe. It is mainly involved in motor function. Neural impulses sent from the primary motor cortex control movement. Skeletal muscles are activated when signals sent from the primary motor cortex cross the body’s midline. This stimulates the opposite side of the body, which means that the left hemisphere controls the right side of the body and vice versa. Many motor problems can occur when the primary motor…

Everyday Helga walks in the morning with her neighbor. Each day she is noticing that she has to stop sooner because her legs feel as if she ran a mile. Helga didn't think much of it until her neighbor tells her that she's walking half as fast as she usually does, but in reality she feels exhausted. How can she be walking slow? If you have this degenerative disease, weakness in your legs is the first sign. Most people do not realize they have Parkinson's because the earlier symptoms are very…

Abstract Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to the sources of the labeled terminals. VGLUT1 is associated with terminals of auditory nerve fibers, whereas VGLUT2 is associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig and rat have shown that cochlear damage results…

Introduction Volatile inhaled anesthetics are commonly used for general anesthesia worldwide because of their fast action and easy management. However, there is accumulating evidence indicating that general anesthetics that activate gamma amino butyric acid (GABA) receptors induce widespread apoptosis at a clinically relevant concentration in the developing brain of rodents [1, 2, 3]. Furthermore, anesthetic administration in children causes long-term impairments of cognitive behavior later in…

Selegiline is an irreversible monoamine oxidase (MAO) inhibitor typically used in the treatment of Parkinson’s disease. Monoamine oxidase A (MAO-A) generally metabolizes tyramine, norepinephrine, serotonin, and dopamine, whereas in comparison, monoamine oxidase B (MAO-B) metabolizes mostly dopamine (Youdim, Edmondson, & Tipton, 2006). Following conversion by MAO to its active form, selegiline inactivates MAO by irreversible binding to MAO-B. The differences between the selectivity of the two…

Log concentration-response curve to carbachol in the absence or presence of a series of concentrations of antagonist were showed on Figure 1. The log concentration-response curve has a characteristic sigmoidal shape. The addition of higher concentration of antagonist into the organ bath made the curves gradually shift to the right in a nearly parallel manner (Fig 1). The higher concentration of Atropine, the more its curve moved to the right of the graph. However, these effects of antagonist did…