Gaylord D. Ellison - US grants

Tardive dyskinesia develops in a substantial proportion of humans treated with chronic neuroleptics. Although some antipsychotic drugs may have a lessened propensity for inducing this disorder, it appears possible that all neuroleptics, if given in similar amounts for similar periods, will carry a substantial risk for inducing this syndrome. This has led clinicians to attempt to decrease the incidence of tardive dyskinesia by giving periodic drug-free intervals, or "drug holidays". However, retrospective clinical studies are very unclear as to whether this practice is beneficial or actually deleterious, and animal studies suggest drug holidays can have either positive or negative effects depending upon precise experimental details. It is proposed here to study, using an animal model, what are the precise regimens of neuroleptic administration which facilitate or hinder the development of persisting side-effects of chronic neuroleptics. First we will perfect a method for conveniently delivering very constant levels of haloperidol to rats over prolonged periods of time and develop an automated procedure for precisely quantifying and identifying subcomponents of the "vacuous chewing movements" which develop in rats administered chronic neuroleptics. Using these procedures the role of dosage and length of drug administration in determining the course of development of these abnormal oral behaviors and their persistance following drug discontinuation will be studied. It is then proposed to determine the exact experimental conditions under which "drug holidays" in neuroleptic administration can have beneficial long-term effects. Included in these studies will be the determination of optimal drug holiday length, timing, and a comparison of abrupt versus gradual drug withdrawal. It is also proposed to determine whether there are differing degrees of persisting side-effects of chronic neuroleptics when these drugs are chronically administered so as to induce steady serum levels (as occur with depot injections) versus the more fluctuating levels induced by oral administration. These experiments address an important research issue involving a widespread iatrogenic disorder. The experimental questions addressed in this proposal will probably only be answered in the near future using an animal model such as that proposed here.

Tardive dyskinesia (TD) is a severe latrogenic disorder which develops gradually in schizophrenics treated with chronic neuroleptics. This laboratory has developed a highly unique animal model of tardive dyskinesia based upon a computerized system in which measures of oral movements (OMs) in rats are directly placed into computer memory together with the reports of human observers. The results obtained using this highly novel and rigorous approach are very different from those obtained using simple observational techniques, and suggest the best model of TD in rats is the tiny tremorous oscillations of the lips which rats begin to show only after many months of chronic neuroleptic administration and which are largely undetected by the naked eye. We now propose to further investigate this promising animal model of tardive dyskinesia by clarifying, through further computer analysis and amplified recording procedures, what the small oral oscillations actually represent. Other studies will access whether different regimens of neuroleptic administration alter the development of persistant side effects of chronic neuroleptics, including whether fluctuating or very steady levels of neuroleptics are more prone to induce the disorder. We also propose to compare the extent to which various classes of neuroleptics (including several novel, atypical neuroleptics) induce this disorder, and whether the concurrent administration of selected dopamine stimulants (D1 v. D2 agonists) facilitate or hinder the development of the syndrome. Other studies will further investigate the pharmacology of oral movements using drugs which act on dopamine, or acetylcholine, or GABA systems within the brain, and then compare effects of these compounds on TD-like vacuous OMs in chronic animals. Detailed regional, autoradiographic studies of receptor binding will be conducted on chronic neuroleptic animals at the completion of these experiments so that varying degrees of symptomatology can be correlated with regional alterations in brain biochemistry. These experiments address an important research issue involving a widespread iatrogenic disorder. The experimental questions addressed in this proposal will probably only be answered in the near future using an animal model such as that proposed here.

Tardive dyskinesia (TD) develops gradually in schizophrenics given chronic neuroleptics. Rodent models of TD are highly controversial. This laboratory has developed a very unique rat model of TD based on a computerized system whereby measures of oral movements (OMs) in rats are directly placed into computer memory together with the reports of human observers. Using this model, we have demonstrated an artifact related to activity levels in the test used by other laboratories, one that can lead to spuriously inflated oral movement scores and which may help to clarify this controversial field. We have found that rats treated with continuously administered "typical" neuroleptics do not necessary develop more oral movements per se, but rather gradually develop OMs which have an altered and abnormal form, most notably increased energy at 1-2 Hz. This is an important finding, for this is precisely the altered energy spectrum reported in humans with TD. We have further found that a completely different, "primed dystonia" syndrome (large amplitude, rapid (4-7 Hz), gaping OMs) develops in rats given comparable neuroleptics but in a highly fluctuating regimen (once per week large injections). While "atypical" neuroleptics (clozapine and raclopride) do not induce these syndromes, with clozapine it seems that the TD-like profile gradually develops but its expression is inhibited. Studies of a variety of brain receptors demonstrate persisting altered D2 and GABA receptors in these animals, but similar changes are observed following continuous and intermittent HAL, i.e. in rats which manifest completely different behavioral syndromes. Rats treated with these chronic neuroleptics also gradually develop very small OMs, so small that only the computer can detect them, an effect which deserves further investigation. We propose to pursue this model, which we argue is presently the best viable rodent model of neuroleptic-induced oral dyskinesias, by studying how drugs which affect dopamine or cholinergic receptors, as well as other pharmacological agents, alter the form and frequency of the two neuroleptic-induced oral syndromes. We further propose studies designed to map the underlying brain circuitry, attempting to determine the location of the altered pattern generator using local injections of agonists or discrete brain lesions. Other studies will study effects of aging and atypical neuroleptics. We also propose to determine whether other syndromes reported in humans also develop in these rats, such as an akathisia-like inability to remain still, and if rats also develop the "primed dystonia" syndrome reported in primates. In addition, recordings from humans with TD will be collected and the rom of their movements compared to those from rats administered similar drugs. These experiments address an important research issue involving a widespread iatrogenic disorder; the questions addressed will probably only be answered using a model such as that proposed here. They are of unusual clinical significance, but also represent a basic advance in scientific technology, for the computerized techniques we have developed for the measurement of behavior represent a highly evolved analysis system.

Both amphetamine (AMPH) and cocaine (COC) addicts develop binge patterns in which the drug is frequently administered over prolonged periods of time, producing a nearly continuous intake regimen. For both drugs, during these runs dysphoria and paranoia progressively increase. Similarly, both AMPH and COC, when administered continuously to animals, induce clear stages of behavior, with initial exploratory and stereotypy phases and the eventual development of a "late-stage" characterized by hallucinogen-like behaviors. Yet the two drugs have been found to be quite dissimilar many of the persisting effects on brain they produce when delivered continuously'. Continuous AMPH has a selective neurotoxic effect on caudate dopamine terminals, whereas COC does not, and continuous COC induces persisting alterations in cholinergic and GABA receptors, especially in caudate, whereas AMPH does not. In recent studies of degeneration patterns following continuous AMPH and COC administration we have discovered that both drugs similarly induce highly specific degeneration of axons in the lateral habenula (LH) and fasciculus retroflexus (FR). We now propose to further study this phenomenon in detail. We will further characterize pattern and extent of degeneration, determine the doses and duration of drugs necessary to induce it, and attempt to clarify the neurotransmitters of the degenerating axons and the location of their cell bodies. Using lesioning techniques, receptor blockers, and direct agonists we will attempt to determine what neural pathways and neurotransmitters mediate this effect. In behavioral studies, we will attempt to determine persisting effects of these degenerated axons and whether surgical transections of the principal pathways involved alter the sequence of behaviors observed following continuous COC, especially during repeated binges similar to those in the very chronic addict. Microdialysis techniques will be used to test, in caudate, the important hypothesis that FR axons which degenerate mediate part of the negative feedback circuitry regulating dopamine release. This will be done by measuring in drug-naive and animals pretreated with COC pellets the levels of dopamine and GABA induced by doses of the Dl agonist SKF38393. In secondary experiments we will also further study the pronounced degeneration in hippocampus and parahippocampus which we have recently found following continuous administration of phencyclidine, which is a second and important drug model of psychosis. This laboratory is in a unique position to conduct these studies because of our expertise in slowrelease drug pellets, degeneration patterns, and behavior.

9451080 Beatty This proposal seeks funds to enrich the undergraduate neuroscience laboratory experience at UCLA by extending current exercises and experiments into the domain of the neuron and the genome. Two new neuroscience laboratories -the Interdisciplinary Neuroscience Laboratory and the Behavioral Neuroscience Laboratory -will benefit from the grant. The requested instrumentation will give students experience in intracellular microelectrode recording from cultured Aplysia neurons, the source of much basic knowledge of neuronal function; patch-clamp recording from PC-12 and N1E1-15 cells studying ion channels and receptors; and restriction analysis of DNA and DNA sequence analysis for identifying a series of clones that are expressed primarily in the brain. Patch-clamp and molecular biological methods will bc used together to study the properties of expressed receptors, channels, pumps, and other important membrane proteins in the Xenopus oocyte system. All these exercises are at the forefront of contemporary neuroscience and technically are well within the grasp of university undergraduates. Both the departmental and the interdisciplinary neuroscience laboratories are team taught, with each faculty member teaching a module in his or her own area of expertise. Up to date documentation and instructional material for all laboratory modules will be made available to all colleges and universities over Internet.