This website uses cookies to ensure you have the best experience. Learn more

Epileptogenesis: Gabaa Receptor Subtypes In Human Temporal Lobe Epilepsy

1647 words - 7 pages

Partial epilepsy often results from a brain insult. The development of epilepsy in this situation is termed epileptogenesis. Describe the changes in GABA(A) receptor mediated transmission that occur with epileptogenesis in the hippocampus, and the implications that such changes have for the development of epilepsy. 2010

Epilepsy is a quite common disorder that about 0.5-1 in 100 people are affected. It could happen through entire life but have a higher incidence in young children and elderly. The onset of the seizure is normally spontaneous without an immediate cause. During the seizure the patients show an abnormal excessive neuronal activity in the brain. The reason of the epilepsy is complex, as both environmental and genetic factors could play a role individually or together. While the genetic mutation is more common in children, brain insult such as trauma, stroke could be the main reason for elder people. Despite various reasons, in most condition of epilepsy a region of neuron network is promoted with increase excitability such as increased glutamate release, upregulated NMDA receptors, and/or less inhibition. Generally the inhibition in the brain is mediated by GABA receptors, by hyperpolarizing the neurons via chloride channels. This essay will focus on the change of GABA receptors, especially fast ionic GABAARs, that occur with the epileptogenesis in the hippocampus and its implacations.

Both animal and human experiments have demostrated that epileptogenesis is associated to the GABAARs subunit alteration.

In rat models, by patch-clamping recording and single cell mRNA amplification of dentate granule cell, Brooks-Kayal et al (1998), have found the α4 unit of GABA receptors increased whilst the α1 unit decresed. The subunit alteration occurred after induction of status epilepsy by pilocarpine, and was preceded to the onset of spontaneous seizure. Apart from the morphological change, the pharmacology of the GABAR changed as well. Both efficacy and sensitivity of GABAR boost after epilepsy.

In human model (Loup et al., 2000), GABAAR subunits containing α1, α2, α3, β2, β3, and γ2are stained by immunohistochemistry. Although some other subunits are not studied, these subunits consist of 80% of all GABAAR. While the β2, β3, and γ2 present in most receptors, the α-subunits determine the distribution and pharmacological properties. Consisting with the animal model, the loss of α1 subunit was observed on most region of hippocampus, while an upregulation of α2 subunits occurred on the soma and apical dendrite.

Even though, the alteration of GABA receptor structure is proved to associate with epileptogenesis. It is still unclear, and hard to prove whether the receptor plasticity is a compensatory effect of the other epileptogenesis factors, or the change itself induce the epilepsy.

The dysfunction of synaptic GABAergic signaling contributes to epileptogenesis and generation of seizure. Generally, there are vast number of GABAergic...

Find Another Essay On Epileptogenesis: GABAA Receptor Subtypes in Human Temporal Lobe Epilepsy

The Temporal Lobe and its Effects on Language

1326 words - 5 pages problems in the human temporal lobe. A pivotal area of the temporal lobe and language comprehension is the Wernike’s area. When theirs damage to this section of the brain a condition related to language problems is known as Wernike’s Aphasia. Aphasia is known as a severe language impairment but with this version the person is still able to speak fluently but are unable to comprehend written and spoken language. (Kalat

Ethnic Poverty and Inequality in the UK

2695 words - 11 pages for seizure activity (Duncan J S., 2002). - Radioisotopes are injected into the body. PET - Measures glucose metabolism, central benzodiazepine receptors, opioid subtypes and dopamine receptors (Duncan J S., 2002). - Highest diagnostic activity in temporal lobe epilepsy (Spencer S et al., 1995). - Overall it is able to look at a wide array of functions (Tharin S et al., 2007). - Identifies area of seizure focus (Tharin S et al., 2007

Hope for Moms With Epilepsy

3361 words - 13 pages and with other anti-convulsants. Vigabatrin helps with complex partial seizures with other prescribed medication. (The Merck Manual of Medical Information, 2008) There are many types of surgery to help get rid of the problem that is known as epilepsy there is temporal lobectomy is where they remove the temporal lobe or the only part of the brain known as the temporal lobe. People that have epilepsy can get the temporal lobe is the part of the

Alzheimer's Changes Brain Functionality

1095 words - 4 pages affects. Not all of the results of damage to the brain listed above were exhibited in my grandmother, but it is evident to me now why my grandmother behaved the way she did. Each component of the brain is essential to a normal fully functional life. I know I don’t take my brain for granted anymore. References: Milner B; Visual recognition and recall after right temporal-lobe excision in man. Epilepsy Behav. 2003 Dec;4(6):799

The ‘Glutamate Theory’ of the Pathogenesis of Schizophrenia

2452 words - 10 pages be seen to buttress the glutamate theory of schizophrenia (Jarvitt & Frusciante, 1997) The glutamate hypothesis of schizophrenia speculates that the role of the N-methyl-D-aspartate (NMDA) receptor is pivotal in this disease. NMDA receptors are the major subtypes of glutamate receptors and umpire slow excitatory postsynaptic potentials (EPSPs). These slow EPSPs are deemed critical for the correct demonstration of difficulty for instance, daily

Epilepsy

948 words - 4 pages . A temporal Lobectomy is a common surgury to stop partial seizures. This surgery removes the temporal lobe of the brain. In seventy percent of patients that have had a temporal Lobectomy are seizure free after surgury. The second type of surgery involves disconnecting the two hemispheres of the brain. This is called a corpus callosotomy. The corpus callosum is the bundle of nerves that connects the two halves of the brain. When a person has a

the cerebrum

959 words - 4 pages impulse must travel down an axon to the synaptic terminal. So basically a neuron is sending information to another neuron so the brain functions. (The synapse. (1996)) Overall the brain will mainly be the most important part of the human body. The brain has specific controls to every part in the body. There are four lobes controlling different parts in the body. Those lobes are Temporal lobe, Occipital lobe, Parietal lobe, and the Frontal lobe

Anti-Convulsant Activity of Coleus amboinicus (lour.)

738 words - 3 pages . Apigenin is a naturally occurring flavonoid which was reported to be present in the plant Coleus amboinicus [20]. The apigenin and its derivatives are ligand for the benzodiazepine binding site in the Gamma-Amino butyric acid (GABA) receptor type A (GABAA) and have anxiolytic properties [21]. So, anxiolytic effect of apigenin and its presence in the plant may contribute to the anticonvulsant property of the extracts. The actual phytoconstituents(s

brain and nerves system

3578 words - 15 pages bottom), three edges (the upper, the medial and the bottom and three poles (the frontal, the occipital and the temporal) . Giri ans sulci divide each hemisphere into the frontal (responsible for motor skills, knowledge, inferior frontal lobes is responsible for active behavior) The frontal lobe of the cerebral hemispheres located in front of roland sulcus and includes the precentral gyrus, premotor and prefrontal zone. On the outer surface of the

The Controller of Humans

1260 words - 6 pages The human brain is composed of many important parts of everyday life. The exterior part of the brain has 9 part in which include are divided into different sections, lobes, cortex, and areas. Within the lobes, it includes frontal, parietal, occipital, and temporal lobes. In cortexes, it has the motor cortex, and the sensory cortex. Within the areas section it includes Broca’s Area. The cerebellum is a small version of the brain, and the cerebrum

The Therapeutic Action of Lorazepam

2136 words - 9 pages neurotransmitter GABA. Lorazepam and other benzodiazepines do not bind directly to the same receptor site as the endogenous GABA neurotransmitter does. As you can see from Figure 1 they bind to the benzodiazepine binding sites located in between the alpha and gamma subunits on the GABAA receptors. Once the benzodiazepine locks into the GABAA receptor it alters it, so the neurotransmitter GABA has a much higher affinity for it. Lorazepam doesn’t mimic the

Similar Essays

Temporal Lobe Epilepsy: A Literature Review

1326 words - 5 pages Studies of the disease were found by using the Texas A&M Corpus Christi library through electronic search of temporal lobe epilepsy. Four primary research and one review article were used to complete this literature analysis. The articles discussed are condensed in Table 1. Regarding EI in patients with TLE and patients with extra temporal lobe epilepsy was a case-control study that had three groups. Group 1 consisted of forty patients with

Temporal Lobe Epilepsy: A Literature Review

1162 words - 5 pages Regarding EI in patients with TLE and patients with extra temporal lobe epilepsy discussion verifies the concept of EI. EI is the skill to 1) comprehend emotions and express feelings, 2) comprehend others emotions and sympathize with them, 3) regulate emotions, 4) use emotions as an adaptive function, 5) the use of self-motivation in a positive manner [1]. The anatomical structure of the brain known as the amygdala is vital to emotional

Beta Adrenergic Receptor Variants In Human Hypertension

976 words - 4 pages , one cannot limits particular genes encoding certain class of proteins could probably responsible in hypertension regulation. Convincing evidence for the identification of a true functional polymorphism for hypertension should come from diverse sources, mostly from both population and functional studies. The β2-adrenergic receptor (ADRB2) may represent such a functional candidate gene [3]. The human ADRB2 is a member of the G-protein-coupled

Epilepsy Essay

4060 words - 16 pages , 1995). The variations are divided into two groups, ictal electrograph abnormalities, which are disturbances resulting from seizure activity, and interictal electrograph abnormalities, or disturbances between seizures. The EEG can also give clues as to which region of the brain the disturbances arise from. Interictal temporal spikes will predict the side of seizure origin in 95% of patients if three times as many spikes appear in one temporal lobe