PubMed Health⌕ Search

Biomedical subjects

R L Findling

Publications and source records attributed to R L Findling.

42 records · Page 3Linked to original sources
PubMed1995

Adolescent schizophrenia: a methodologic review of the current neuroimaging and neuropsychologic literature.

This paper reviews all relevant articles that reported structural neuroimaging or neuropsychological data in adolescent patients with schizophrenia. These papers were subsequently examined from a methodological perspective. Few papers have been written that have examined whether adolescent schizophrenia is associated with structural neuroimaging abnormalities or cognitive dysfunction. In these studies, major methodologic issues exist. Therefore, at present, firm conclusions cannot be made regarding the presence or absence of neuropsychologic dysfunction or structural neuroimaging abnormalities in this population. Attention to certain methodologic issues may improve future studies of this topic.

Adolescent↗
PubMed1987

A fluid percussion model of experimental brain injury in the rat.

Fluid percussion models produce brain injury by rapidly injecting fluid volumes into the cranial cavity. The authors have systematically examined the effects of varying magnitudes of fluid percussion injury in the rat on neurological, systemic physiological, and histopathological changes. Acute neurological experiments showed that fluid percussion injury in 53 rats produced either irreversible apnea and death or transient apnea (lasting 54 seconds or less) and reversible suppression of postural and nonpostural function (lasting 60 minutes or less). As the magnitude if injury increased, the mortality rate and the duration of suppression of somatomotor reflexes increased. Unlike other rat models in which concussive brain injury is produced by impact, convulsions were observed in only 13% of survivors. Transient apnea was probably not associated with a significant hypoxic insult to animals that survived. Ten rats that sustained a moderate magnitude of injury (2.9 atm) exhibited chronic locomotor deficits that persisted for 4 to 8 days. Systemic physiological experiments in 20 rats demonstrated that all levels of injury studied produced acute systemic hypertension, bradycardia, and increased plasma glucose levels. Hypertension with subsequent hypotension resulted from higher magnitudes of injury. The durations of hypertension and suppression of amplitude on electroencephalography were related to the magnitudes of injury. While low levels of injury produced no significant histopathological alterations, higher magnitudes produced subarachnoid and intraparenchymal hemorrhage and, with increasing survival, necrotic change and cavitation. These data demonstrate that fluid percussion injury in the rat reproduces many of the features of head injury observed in other models and species. Thus, this animal model could represent a useful experimental approach to studies of pathological changes similar to those seen in human head injury.

Animals↗
PubMed1986

Mnemonic correlates of unit activity in the hippocampus.

The role of the hippocampus in memory processing was examined by recording single unit activity while rats performed two different types of memory tasks. The same apparatus was used for all tasks; it consisted of two goal boxes, side by side, on the end of a runway. One goal box was white, the other was black. Experiment I used a working memory, delayed match-to-sample (DMTS) task. A trial began with a sample phase in which the rat was forced to a goal box containing a reward. The rat was then placed at the beginning of the runway again for the choice phase and allowed to enter either of the two goal boxes. Entering the goal box with the same color as that entered during the sample phase was rewarded. Experiment II used a within-subjects, within-units, design to test rats in two reference memory tasks, a cue task and a spatial task. During the cue task, the rat was rewarded for choosing the same colored goal box on each trial regardless of its spatial location. During the spatial task, the rat was rewarded for choosing the goal box in a specific location on each trial regardless of its color. During all tasks, the location of the goal boxes was changed between trials in a pseudorandom, counterbalanced fashion so that each colored goal box was on the right for half of the trials and on the left for half of the trials. During performance of the DMTS task, activity of most units was correlated with a combination of factors such as color and location, or color and phase. For example, most units showing differential activity in one of the colored goal boxes fired more when that box was in a certain spatial location, or during either the sample or choice phase. During performance of the reference memory tasks, the activity of most units was not correlated with behavior. However, the rate for some units changed between the cue and spatial tasks. When unit activity was correlated with behavior, it was dependent on a combination of dimensions such as color and spatial location. These results demonstrate that units in the hippocampus respond to combinations of stimulus dimensions such as color and spatial location, and to the temporal context necessary to solve a working memory task.

Animals↗
PubMedDate not supplied

Pharmacological treatment of depression in children and adolescents.

Major depression is a common disorder during childhood and adolescence. Over the past decade, many new antidepressants have been marketed in the US. In adults, these newer agents have been shown to be as effective as the prototypic tricyclic antidepressants (TCAs). Further, when compared with the TCAs these medications are better tolerated and are safer in overdose. Although TCAs are effective in the treatment of depressed adults, controlled clinical trials have not demonstrated their efficacy in either children or adolescents. In addition, concerns about the safety of TCAs and the monoamine oxidase inhibitors has left disappointingly few pharmacological treatment options available for depressed children and adolescents. For this reason, clinicians have begun to prescribe the newer agents for this population, despite the fact that relatively little is known about their disposition, safety or effectiveness in the young. Investigators have begun to examine whether the use of newer antidepressant medications such as fluoxetine, sertraline, paroxetine, fluvoxamine, nefazodone, and venlafaxine is truly indicated for children and adolescents with major depression. Pharmacokinetic studies of sertraline, paroxetine and nefazodone have been performed in depressed youths. The results of these studies have provided data for rational administration strategies for these agents. They have also provided evidence that these agents may be well tolerated in children and adolescents. Further evidence that these agents are often well tolerated when prescribed to depressed youths has been obtained from both open-label and double-blind studies. Published studies have generally shown that open-label treatment with these newer agents often leads to symptom amelioration in paediatric patients with major depression. Since high rates of placebo response are often seen in depressed children and adolescents, results from these studies cannot be interpreted to suggest that these medications have true antidepressant efficacy in this population. At present, the results of only two such studies have been published. The results of one of these trials are difficult to interpret because of methodological considerations. The other study reported that treatment with fluoxetine was superior to placebo. This paper critically reviews what has been published about the pharmacological treatment of depressed paediatric patients and provides some guidance to the use of antidepressants in this patient population, paying particular attention to what is known about the newer antidepressants as well as considering directions for future research.

Adolescent↗