Exam 3 Review Session
Exam 3 Review Session NSCI 3310
Popular in Cellular Neuroscience
Popular in Nutrition and Food Sciences
verified elite notetaker
This 6 page Class Notes was uploaded by Emma Notetaker on Saturday November 7, 2015. The Class Notes belongs to NSCI 3310 at Tulane University taught by Jeffrey Tasker in Summer 2015. Since its upload, it has received 55 views. For similar materials see Cellular Neuroscience in Nutrition and Food Sciences at Tulane University.
Reviews for Exam 3 Review Session
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/07/15
Exam 3 Review 11/7/15 8:18 PM • ionotropic ONLY open channels • metabotropic can both open AND close • shunting inhibition • shunting of current out of cell via open chloride channels o changes resistance of these cells o GABAA receptors open chloride channels (which have equilibrium potential very close to membrane potential, so little driving force) o little net flow of chloride, BUT because all of these channels are open, positive charge can move § chloride ions drawn to negate this charge o shunting charge out of cell to extracellular space o for given synaptic current at excitatory synapse, with decrease in resistance you will get a smaller voltage response o represented by Ohm’s law • GPCR’s • 2 isoforms of GABAB receptors that come together and dimerize in order for GABA to activate 2 ndmessenger pathway • one isoform binds to GABA, one interacts with G protein o MUST come together to make full response G protein activation • receptor activated • GTP subs for GDP • B/y dimer comes apart, a signals to second messenger cascade o B/y signals directly to channel (GIRK channels – K channels) § directly activates G proteins § GIRK is G protein inwardly rectifying potassium channel cAMP (adenylyl cyclase is primary effector enzyme, which leads to cAMP production) • GI – inhibitory – less cAMP produced and less PKA • GS – activates adenylyl cyclase to make more PKA phosphoinositol • GQ stimulate phospholipase C (PLC) • PIP2 is a membrane lipid precursor which makes IP3 and DAG • IP3 and DAG o IP3 is soluble, goes into cytosol and interacts with specific receptors on ER, increases calcium concentration § calcium acts as second messenger § facilitates PKC activites o DAG is lipid kinases phosphorylate proteins which changes conformation and activity modulation • ionotropic receptors (primarily glutamate and GABA receptors) responsible for ALL FAST SIGNALS • all nt using GPCRs are modulating these fast on/off responses by increasing or decreasing excitability OR changing probability of nt release postsynaptic receptor • depolarization in response to activation of GPCR for minutes at a time o caused by opening of Na channels OR closing of K channels postsynaptic modulation • synapse on postsynaptic neuron that is UPSTREAM of initiation site of AP • influencing whether or not cell will generate AP presynaptic modulation • axoaxonic • all you need are receptors (no need for synapse) • spillover of nt into synaptic cleft o activates another synapse with extra nt that were in the synapse • methods: o 1. spillover from autoregulation o 2. spillover of nt from adjacent synapses o 3. axoaxonic synapses • change calcium influx OR change intracellular proteins responsible fro exocytosis à this is the way it influences nt release sensory receptors • quality (modality) - 5 o vision, hearing, touch, etc somatic • quality o 3 submodalities § 1. touch and pressure § 2. temp § 3. pain o mechanoreceptors – touch § more superficial have finer resolution due to smaller receptive fields o free nerve endings in skin regulate temperature • intensity o threshold o frequency/duration coding o receptor potential is PASSIVE – transmitted from tip to initial trigger zone of axon where there are more Na channels § AP generated if reaches threshold • location o receptive field o spatial resolution determined by density of receptors § 2 point discrimination § biggest parts of cortex devoted to places on skin with more receptors o dermatomes § primary sensory neurons on spinal cord • duration o slow receptors – tonic (continuous, sustained info) o fast receptors § transient signals organization – ALWAYS second order neurons that cross midline • dorsal column medial lemniscu o ipsilateral UNTIL medulla where it crosses over to other side’s somatosensory cortex • spinothalamic crosses RIGHT at spinal level somatosensory cortex in parietal lobe lateral inhibition • higher order neurons getting inputs from lower order neurons • spatial resolution refined because all neurons sending inhibitory connections through inhibitory interneurons inhibiting neighbors o whoever is activated most with strongest response will send strongest inhibitory response to neighbor o this wil be the center, so we can tell most where the signal is 11/7/15 8:18 PM 11/7/15 8:18 PM
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'