35 research outputs found
Effects of an ACTH 4-9 related peptide upon intracranial self stimulation and general activity in the rat
Adult male Sprague-Dawley rats were stereotactically implanted with electrodes within the anterior medial forebrain bundle: The rats were trained to respond for intracranial self-stimulation (ICS) and treated with control solution or varying doses of an ACTH 4-9 related synthetic peptide (Org 2766; H-Met(O 2 )-Glu-His-Phe- d -Lys-Phe-OH). The drug affected ICS as measured in overnight response records, with the highest dose reliably increasing the amount of responding. In a second experiment rats were similarly treated and general activity was assessed. No remarkable changes in activity were present at any tested dose. The findings corroborate previous reports suggesting ACTH-related peptides may be active in a variety of motivated tasks, but less active with respect to general activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46417/1/213_2004_Article_BF00433254.pd
Antidepressant-like activity of magnesium in the olfactory bulbectomy model is associated with the AMPA/BDNF pathway
Antidepressant effects of standardized extract of Commiphora mukul Engl. in olfactory bulbectomized rats
Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease
Classification of neuromuscular blocking agents in a new neuromuscular preparation of the chick in vitro
A neuromuscular preparation of the chick is described:
1. 1. The sciatic nerve-tibilis anterior muscle preparation of the 2–10 days old chick fulfils all criteria of an assay preparation and differentiates between curare-like and decamethonium-like agents.
2. 2. The preparation responds to supramaximal nerve stimuli with twitches, which are of constant height during 6–8 hr. The twitch amplitude is decreased by curare-like drugs in concentrations of 0.5 μg/ml and more. This effect is dose-dependent.
3. 3. The preparation responds to the administration of decamethonium-like drugs with a slow contracture, the force and velocity of which is dose-dependent, and a decrease in the height of the twitch. The time curve of these two effects of decamethonium-like drugs is not the same. Threshold dose for contractures is about 0.1 μg/ml.
4. 4. Curare-like compounds in doses of times threshold and more antagonize or prevent the slow contractures caused by decamethonium-like drugs, dose-dependently.
5. 5. The effects are easily reversible and also reproducible in the same preparation during a day.
6. 6. A resemblance is suggested between the chick slow fibre response and the responses of the cat extra-ocular muscle and the mammalian intrafusal muscle to decamethonium-like compounds; the possibility of a presynaptic site of action apart from a post-synaptic one of the decamethonium-like drugs in the chick muscle is postulated
The effects of ACTH- and vasopressin-analogues on CO2-induced retrograde amnesia in rats
Amnesia for a one-trial step-through passive avoidance response was induced in rats by application of CO2 until respiratory arrest occurred. The ACTH-analogue ACTH4–10 alleviated the amnesia when administered 1 hr prior to the retrieval test but not when given 1 hr prior to the acquisition trial. The behaviourally inert ACTH-analogue ACTH11–24 appeared to have no effect on the amnesia. The vasopressin-analogue desglycinamide lysine vasopressin (DG-LVP) antagonized the amnesia when administered 1 hr prior to the acquisition trial or 1 hr prior to the test trial. The relevance of these date to present theories on amnesia is discussed