ABSTRACT
Male rats, 90-100 days old, with frontal cortex lesions were given either subcutaneous sterile water (SW) as a vehicle control or 1, 10, or 100 micrograms of BIM-22015 every other day for 20 days. Brain-injured subjects tested in the Morris water maze with either 10 micrograms BIM-22015 or SW took significantly more trials than sham-operated rats to locate a submerged platform eight consecutive times within 60 s. The animals given 1 or 100 micrograms BIM-22015 took significantly fewer trials to reach criterion than brain-injured animals in the other drug treatment groups. On a percentage of savings, measured 8 days after reaching criterion, the brain-injured subjects given 1, 10, or 100 micrograms BIM-22015 did not differ from sham-operated rats. In contrast, the brain-injured animals given SW took longer to find the submerged platform than they did during the initial training. To assess long-term effects of the ACTH analog treatment, rats were trained on a delayed spatial alternation task 30 days after receiving the last injection. On this task, brain-injured rats treated with the 10-micrograms dose performed significantly better than those given sterile water. Acetylcholinesterase (AChE)-labeled neurons counted in the nucleus basalis magnocellularis indicated that rats with frontal cortex damage given the 10-micrograms treatment did not differ from the sham controls and had significantly more AChE-positive neurons than injured counterparts treated with SW or 100 micrograms.
Subject(s)
Adrenocorticotropic Hormone/pharmacology , Discrimination Learning/drug effects , Frontal Lobe/injuries , Mental Recall/drug effects , Nerve Regeneration/drug effects , Orientation/drug effects , Peptide Fragments/pharmacology , Acetylcholinesterase/physiology , Animals , Brain Mapping , Cholinergic Fibers/drug effects , Escape Reaction/drug effects , Frontal Lobe/drug effects , Male , Neurons/drug effects , Rats , Retention, Psychology/drug effects , Structure-Activity RelationshipABSTRACT
Adult, male Sprague-Dawley rats received 100 mg/kg Ginkgo biloba extract (GBE) intraperitoneally for 30 days. GBE reduced overall activity and decreased sensitivity to light in the open field maze. The rats were also less responsive to noxious stimuli after 13 days of treatment with GBE. After the last injection, all subjects were trained on a delayed-spatial alternation task. Subsequent to acquisition of the spatial task, the rats received either sham operations and saline or bilateral frontal cortex lesions treated with either saline or GBE. Thirty additional days of treatment began on the day of injury, and open field behavior, analgesia, and metabolic activity measurements were again measured. The rats with lesions treated with saline were more active than their GBE-treated counterparts and sham controls but there were no differences in response to illumination or noxious stimuli. Retention of the delayed-spatial alternation indicated that rats with lesions treated with GBE were less impaired than brain-injured subjects receiving saline treatment. Histological examination showed that GBE reduced the extent of brain swelling in response to the injury.
Subject(s)
Brain Injuries/psychology , Plant Extracts/pharmacology , Wounds, Penetrating/psychology , Animals , Behavior, Animal/drug effects , Brain/pathology , Brain Injuries/metabolism , Brain Injuries/physiopathology , Hot Temperature , Learning/physiology , Male , Motor Activity/physiology , Pain , Rats , Rats, Inbred Strains , Retention, Psychology/physiology , Space Perception/physiology , Wounds, Penetrating/metabolism , Wounds, Penetrating/physiopathologyABSTRACT
Pseudopregnant and normal cycling female Sprague-Dawley rats were trained on a delayed-spatial alternation task. After acquisition training, the subjects received frontal cortex lesions and were subsequently tested for retention. The pseudopregnant animals with lesions were less impaired than their normal cycling counterparts. Learning and retention testing were not affected by hormonal status in the noninjured controls. Histological examination showed that the normal cycling rats with frontal cortex lesions possessed enlarged ventricles, indicating the presence of edema in this surgical group. However, brain tissue of pseudopregnant subjects given the same lesion and sham operates of both hormonal states did not display this characteristic of edema. We speculate that the behavioral and anatomical impairment observed in the normal cycling females with brain injury is due to higher levels of vasopressin, a potent vasoconstrictor synchronized with brain injury in our manipulation.
Subject(s)
Estrus/physiology , Frontal Lobe/physiology , Memory/physiology , Retention, Psychology/physiology , Animals , Conditioning, Operant/physiology , Discrimination Learning/physiology , Estradiol/blood , Female , Orientation/physiology , Progesterone/blood , Pseudopregnancy/blood , Rats , Rats, Inbred StrainsABSTRACT
Fetal brain tissue from the occipital or the frontal cortex was implanted into the damaged occipital cortex of adult rats. The animals receiving grafts of embryonic frontal cortex showed partial restoration of brightness discrimination while recipients given homologous implants of occipital cortex were as impaired as those animals with lesions alone. Neither frontal nor occipital grafts aided in the performance of a pattern discrimination problem; both groups of brain-damaged animals were unable to learn the task. Nonetheless, both groups of animals had viable and enlarged grafts with similar neuronal and glial profiles.
