Gb1r Case Study

Action potentials can occur more frequently as long there is a continued source of stimulation, as long as the relative refractory period has been reached, which in experiment 2 the refractory period was complete.

At the molecular level of explanation these processes are dependent on the interplay between glutamate receptors, Ca2+ channels, the increase of intracellular Ca2+ levels, Ca2+-dependent proteins like Akt, ERK, mTOR and neurotrophins such as brain derived neurotrophic factor (BDNF) (24, 25).

In the Summer of 2015 I had the opportunity of accomplishing my own research project. With the help of my graduate student, I led us to better understand the neural pathway

() who stated that stimulation of dMT axonal fibers with brief light pulses did not evoke fast synaptic inputs in CeL neurons. Only small, slow inward currents were reported following high frequency light stimulation. The diverging results may be the consequence of differing viral transduction efficiency or stimulation conditions. Interestingly, the apparent connectivity of dMT and BA was substantially greater as compared to dMT and CeL. Furthermore, synaptic responses evoked in BA PNs were larger as compared to those in CeL neurons regarding absolute amplitudes of AMPAR- and NMDAR-mediated currents under similar stimulation conditions. The effect may be due to stronger innervation of the BA by dMT efferents, to increased presynaptic transmitter release or to increased postsynaptic receptor expression. The AMPAR/NMDAR ratio, which may give an indication of input-independent basal synaptic strength based on postsynaptic AMPAR occupancy, did not reveal any differences dMT-BA and dMT-CeL synapses. Interestingly, AMPAR silent synapses were discovered in the CeL. These synapses may be recruited during periods of increased synaptic input and facilitate

The problem was that GBH was easily being manufactured and constantly used a rape drug. This particular Act rescheduled GBL as a level one controlled substance in order to harshly punish individuals who make, distribute, and use the drug for violent/sexual acts.

Astrocytes have been shown to communicate amongst themselves, as well as participate in bidirectional communication with neurons via the 'Tripartite synapse '. Ca2+-dependent glutamate release also

Next, Lundgaard et al. (2015) introduced the activity-dependent component to their study by unilaterally stimulating (3 Hz) the whiskers of mice and observing 2DG-IR uptake and neuronal activation. Local field potentials were measured in the contralateral barrel cortex during whisker stimulation to ensure neurons were activated; results confirmed neuronal activation occurred. Further, 2DG-IR uptake was higher in contralateral barrel cortex, compared to ipsilateral. Specifically, uptake in contralateral neurons was significantly increased, whereas, astrocytic uptake was not statistically significant between the two hemispheres. Therefore, stimulation of the sensory system caused activated neurons to take up glucose to a greater extent than surrounding astrocytes.

In this proposal we want to know: 1) the relationship between abnormal cell morphology and temporal lobe epilepsy (the most common type of post-stroke epilepsy) 2) What are the other intrinsic and extrinsic cell changes that occur in this model 3) Whether there is an alteration in the ratio of excitatory and inhibitory inputs to the cell that can ultimately drive TLE. To answer these questions, we will use a transgenic mouse model and neuroimaging techniques to reconstruct the abnormal neurons and then analyze them using neuron tracing software. Additionally, we will use a transgenic mouse combined with advanced tracing techniques to trace abnormal cell inputs.

It is commonly accepted that synapses exist between neurons and reuptake occurs with synaptic neurotransmitters. According to Doctor Jason Pugh’s research, there is much more involved. In conjunction with Trinity’s Biology Department, he spoke about his specific field of study in presynaptic receptors and neurotransmitters. The lecture itself was titled “Cooperative activity of presynaptic GABA receptors modulates neurotransmitter release and information transfer in neuronal circuits”. This lecture provided much insight to the inner workings of neurotransmitters and the processes concerning them.

How 5-HT modulates NMDA receptor activation is a key question of interest. Despite being cation channels, NMDA receptors have non-linear, voltage-dependent conductance (Mayer and Westbrook, 1987). This property results from the voltage-dependent Mg2+ blockade of the receptor channels (Mayer et al., 1984; Nowak et al., 1984) and thus leads to the negative slope conductance in the current-voltage relationship (i.e. I-V curve; Nowak et al., 1984; Flatman et al., 1983; MacDonald et al., 1982). Because of the voltage-dependent conductance, NMDA receptor activation generates intrinsic voltage oscillations in spinal neurons of rat (Hochman et al., 1994a; Hochman et al., 1994b) and amphibian (Sillar and Simmers, 1994a; Sillar and Simmers, 1994b)

In recent years, a growing number of research has looked at the effects of stimulating brain oscillations on memory performance. Brain oscillations are fluctuations in local field potentials, caused by the input of neurons in to a specific cell assembly (Hanslmayr, Staudigl, & Fellner, 2012). In response to a stimulus, alpha (~10 Hz) and beta (~15-30 Hz) oscillation power decrease in activity, while theta (~4-7 Hz) and gamma (~40-100 Hz) oscillations increase (Hanslmayr & Staudigl, 2014). The changes in oscillatory power evoked by a stimulus modulate synaptic plasticity, the basis of memory formation (Düzel, Penny, & Burgess, 2010).

A compound action potential (CAP) is a recording demonstrating the sum of multiple action potential simultaneously occurring in the various axons in a nerve. A CAP relates to the nerve’s excitability, how quickly it generates an action potential, which is associated to its firing threshold. This experiment demonstrates the interconnected effects of stimulus intensity and duration on CAP amplitude. Using extracellular recording, the lowest stimulus intensity was measured for which a CAP was present. This was repeated at various increments of stimulus duration. An inverse relationship between stimulus intensity and duration was observed; when stimulus duration

Astrocytes are the most abundant type of glial cells and their organization in the brain is quite complex. Each astrocyte has its own domain and has the ability to reach more than 100 thousand neuronal synapses at once (Halassa, et al. 2007). In fact, the size of astrocytes increase as the brain functionality become more complex that implies that astrocytes are evolutionary old (Kimelberg and Nedergaard 2010). For a long time, it was believed that astrocytes are only function as a structural support. Indeed, astrocytes are contributing to network activity of neurons. They have and important role in neuronal metabolism, providing neurons with necessary nutrients via vasculature and act as a storage of glycogens to sustain

To determine if the pyramidal cells in the cortex have normal electrophysiological properties, we conducted spontaneous transmitter recordings from putative pyramidal cells in the somatosensory cortex of Nes-cre;RBM8afl/+ mice. Pyramidal cells in the cortex of these knockout mice have a significant decrease in spontaneous inhibitory post synaptic current (sIPSC) frequency, but no changes in sIPSCamplitude, or spontaneous excitatory post synaptic current (sEPSC) frequency or amplitude. This indicates deficits in the presynaptic but not postsynaptic neurons. Deficits could include fewer synaptic vesicles being released or the synaptic vesicles containing less transmitters inside. Given our findings that these mice have fewer PV+ and NPY + cells, we posit that cortical interneurons are releasing normal amounts of GABA, indicating that the change in frequency results from the decrease in interneuron number. However, more experiments need to

When it comes to treatment of GBS, a better outcome is obtained if treatment begins within the first two weeks of the onset of symptoms. It is important to understand that there is no cure for GBS, but treatment can decrease the effects and severity of the symptoms. Two treatments are typically used; and studies have shown that these are equally as effective. These are plasmapheresis treatment and intravenous immunoglobulin. Corticosteroids have been proven inefficient when it comes to the treatment of GBS. The best care consists of one of the two immunotherapies mentioned above, supportive care, and monitoring of respiratory failure. Appropriate antibiotic therapy is provided if needed, as well as pain medications, and psychological care.