Neuronal hyperactivity

Neuronal hyperactivity convulsions impaired vision, concentration, and memory... 

Neuronal hyperactivity, incoordination, tremors with hyperthermia, seizures... 

In conclusion, the data demonstrated that synergistic mechanisms of cellular disruption caused by anticholinesterase agents led to cellular dysfunction and neurodegeneration. It has also been demonstrated that preventing CF-induced neuronal hyperactivity by pretreatment with MEM and atropine blocks pathways associated with oxidative damage in rat brain. The documented abihty of MEM therapy to reduce free radical generation and lipid peroxidation, prevent HEPs and attenuate the morphological injury provides further support for the role of ROS and RNS in anticholinesterase-induced seizures. 

Oral LD50 values in rats range from 133 to 800 mg kg and from 150 to 300 mg kg in mice. In animal models, the main toxic effect of DDT is neuronal hyperactivity. Alterations in the previously... 

McCreery et al. [122] have reviewed damage from electrical stimulation of peripheral nerve. They concluded that damage may be from mechanical constriction of the nerve as well as neuronal hyperactivity and irreversible reactions at the electrode. 

On the pathophysiological side, hyperactive nNOS has been implicated in A/-methyl-D-aspartate (NMDA)-receptor-mediated neuronal death in cerebrovascular-stroke. Some disturbances of smooth muscle tone within the gastrointestinal tract (e.g., gastroesophageal reflux disease) may also be related to an overproduction of NO by nNOS in peripheral nitrergic nerves. 

The dendrites of neurons adjacent to those which degenerate also show extensive growth and sprouting which could facilitate abnormal and disorganised synaptic transmission and cause hyperactivity. It is also known that the dendrites of cells around an alumina focus in monkeys, as well as in human epileptic brain, lose their spinous processes, which might contribute to the paroxysmal discharge by facilitating the spread of depolarisation to the neuron soma. Certainly an increase in the number of Na+ channels on the dendrites of spinal motoneurons, which would facilitate the occurrence of reactive dendritic Na+ spikes, has been seen after axotomy. 

Histamine produces its pharmacological actions by three subtypes of receptors the postsynaptic Hi and H2 receptors and the presynaptic H3 receptor. The H3 receptor is mainly located in the central nervous system (CNS), where it acts as an inhibitory autoreceptor in the central histaminergic neuronal pathways [176]. A number of therapeutic applications have been proposed for selective H3 receptor antagonists, including several CNS disorders such as Alzheimer s disease. Attention Deficit Hyperactivity Disorder, Schizophrenia, or for enhancing memory or obesity control. 

A second theory of phantom pain suggests that second-order neurons in the dorsal horn of the spinal cord become hyperactive. Spontaneous firing of these neurons causes transmission of nerve impulses to the brain and the perception of pain. 

Norepinephrine NE transporter Human cDNA Depression, Alzheimer s disease, epilepsy, anxiety, attention deficit hyperactivity, angina, asthma, cardiac arrhythmia, cardiac hypertrophy, congestive heart failure, myocardial ischemia, hypertension, artherosclerosis, narcolepsy, orthostatic hypotension, prostatic hyperplasia, rhinitis, diabetes, diarrhea, glaucoma, impotence, obesity, opiate withdrawal pain, Raynaud s disease, preterm labor pain Modulation of norepinephrine concentration in the neuronal synaptic clefts, neuroprotection... 

In admittedly oversimplified terms, it is believed that hyperactivity of dopamine neurons in the mesolimbic pathway contribute to the positive symptoms of schizophrenia. All the typical antipsychotics are believed to work by reducing the activity of the mesolimbic dopamine pathway. More specifically, they do this by blocking dopamine receptors on the nerve cells. Over a period of 1-3 weeks, the dopamineblocking effect of the typical antipsychotic begins to relieve the positive symptoms of schizophrenia. 

---