Opioids Flashcards
drugs that reduce pain without producing unconsciousness
narcotic analgesics
The main active ingredient in opium
morphine
Opium has other molecules like ____, ____ and ____, and the small differences in structure determine the _____ and side effects
codeine, thebaine, narcotine, effectiveness
heroin was made by adding two ____ groups to morphine, making it more _____ soluble. It reaches the brain _____, making it more ____ than morphine when injected due to increased ______. It is converted to _____ in the brain. Some opium derivatives are _______, or modified versions of opium ingredients. Other narcotics are entirely ____ and may have very different chemical structures
acetyl, lipid, faster, potent, bioavailability, morphine, semi-synthetic, synthetic
opioid receptors were first discovered using ______ binding assays, before the ____ ligands were identified. Opioid receptors are also in the ____. Selective ones were used to identify receptor subtypes: _____, ____, ____ and _____. Receptor subtypes have distinct _____ in the brain and spinal cord, suggesting they mediate a wide variety of effects. All are ____ ______ metabotropic receptors that inhibit ____ ______
radioligand, endogenous, gut, mu, delta, kappa, NOP-R, distributions, Gi protein-linked, adenylyl cyclase-cAMP
The mu receptor has a high affinity for ____, and regional distribution reflects its effects. Receptors in the medial ______, ____ ____, _____, _____, and ___ ____ mediate the analgesia. Receptors in the ____ mediate cardiovascular / respiratory control, ____ control, and nausea / vomiting. Receptors in the ___ and striatum have a role in sensorimotor integration.
morphine, thalamus, periaqueductal grey, raphe, LC, spinal cord, brainstem, cough, thalamus
mu receptors in the NAcc mediate feeding _____ _______. They mediate pleasurable aspects of ____ foods. Blocking these receptors results in reduction of ____ pleasure. Opioids are also released during _____ encounters
positive reinforcement, fatty, hedonic, sexual
the delta receptor is predominately in _____ structures. The locations suggests roles in ______, motor _____, ________ and _____ function. Reduced delta activity causes ____ in animals. A considerable number of areas overlap with ____ receptors, suggesting modulation of analgesia.
forebrain, olfaction, integration, reinforcement, cognitive, anxiety, mu
the kappa receptor are located in the _____, _____ and ______. They may participate in the regulation of _____ perception, _____ motility, and ______. They were initially identified by binding to ______
striatum, amygdala, hypothalamus, pain, gut, dysphoria, ketocyclazocine
an opioid analog that produces hallucinations and dysphoria
ketocyclazocine
Nociceptin / orphanin FQ receptors are widely distributed in the ____, ___ areas, thalamus, ___ ___ and spinal cord. The receptors are similar to other opioid receptors but do not ____ opioid drugs. Their locations suggest a role in _____, feeding, ____, ____ function, ____ and neuroendocrine regulation. Activation in the ___ _____ produces less _____ vs mu receptors but also has minimal ____ potential and causes less _____ ______. Above the spinal cord, these receptors can produce _______
cortex, limbic, raphe nuclei, bind, analgesia, learning, motor, reward, spinal cord, analgesia, abuse, respiratory depression, hyperalgesia
peptide transmitters that bind to opioid receptors were discovered in the _____ and was called _____. Multiple peptides that activate these receptors were later discovered and called _______.
1970s, enkephalin, endorphins
endogenous opioid peptides are synthesized from larger ____ peptides which are ___ into smaller peptide transmitters in the _____. These _______ contain the amino acid sequence for both endogenous opiates and other transmitters.
precursor, cleaved, terminal, propeptides
some opioid transmitters are released via long _____ projection systems, while other are released by ______ circuit neurons
axonal, local
different variants of endogenous peptides exist such as _____ or ___, met or _________. Endogenous opioid peptides are often _____ with other NTs in the nerve terminals and can be simultaneously released with ____ or ______.
dynorphin-A, B, leu-enkephalin, co-released, Glutamate, GABA
endogenous opiates are not _____ for a receptor subtype, but instead show a _____ preference. the _____ receptor is preferentially activated by endorphins and somewhat selectively activated by ______. The delta receptor is preferentially activated by ____ and _____. The Kappa receptor is preferentially activated by ______.
selective, relative, mu, endomorphins, endorphins, enkephalins, dynorphins
a class of endogenous opiate; propeptide has not been isolated yet
endomorphins
opiates inhibit neural activity in several ways. In postsynaptic inhibition, receptors activate a ____ protein that opens _____ channels causing ______. They can also use presynaptic ________ that activate G proteins that close ____ channels, reducing transmitter _______. They can also use presynaptic autoreceptors to reduce the release of ______ NTs, resulting in a reduced postsynaptic effect
G, K+, hyperpolarization, heteroreceptors, Ca2+, release, co-localized
a partial agonist that is less potent than morphine but also has the risk of respiratory depression and dependence
buprenorphine
opioid antagonists that are fast acting and used for opioid overdose as they prevent or reverse the effects of opioid drugs
naloxone, naltrexone
____ ____ antagonists are harder to dose and disrupt regular functions by opioids
non competitive
endogenous opioids and opioid drugs bind to receptors and inhibit ____ _____ transduction at multiple sites. Within the spinal cord, (_____ ____), opioid _____ can inhibit pain projection neurons. Opioids can also activate _____ pathways originating in the brain that project to the spine to either ______ inhibit pain projection neurons, or inhibit _____ interneurons that synapse onto pain projection neurons.
pain signal, spinal analgesia, interneurons, descending, directly, excitatory
opioid drugs can work in the brain or the _____, and the net effect is to reduce the spinal cord neuron’s activity. Opioids activate two descending pain-inhibiting pathways originating in the ______ ______. This area is rich with opioid peptides and _____. Stimulation induces ____ that can be attenuated by opioid _______. Opioid projections from this area _____ _____ and ____ ____ descending projections that suppress pain signals in the spinal cord. It is very effective because it targets multiple _____.
spine, periaqueductal grey, receptors, analgesia, antagonists, disinhibit, raphe, locus coeruleus, sites
Opioid activity occurs in other _____ locations such as the ____, ____ and ____ areas, which may mediate ______, ______ and or _____ components of pain.
supraspinal, sensory, limbic, hypothalamic, emotional, autonomic, neuroendocrine
