Agonist-to-antagonist spectrum of action of psychopharmacologic agents,

Sample Solution

  The agonist-to-antagonist spectrum of action of psychopharmacologic agents involves substances that interact with neurotransmitters to produce either a stimulatory (agonists) or inhibitory (antagonists) effect on neurons. Agonists activate receptors and generate neuronal depolarization, while antagonists prevent receptor activation and reduce neuronal depolarization. Partial agonists bind to the same receptors as agonists but have a lower efficacy, while inverse agonists bind to the same receptors as antagonists and reduce the activity below baseline levels, thus increasing neuronal inhibition. This can impact the efficacy of psychopharmacological treatments by altering how effectively a given substance interacts with its target receptor in order to achieve desired therapeutic effects.

Oviposition, or the laying of eggs, is broken down into pre-oviposition and post-oviposition. In this experiment we observed pre-oviposition factors using the model species Callosobrachus maculatus, commonly known as the bean beetle. Small and large lima beans were used to test whether or not bean beetles had a preferred site size for oviposition. We hypothesized that if a preference was shown, the majority of eggs will be oviposited on the larger lima beans when compared to small lima beans. To do this we placed 15 small and 15 large lima beans in 3 petri dishes, then added 3 female and 2 male bean beetles in each and waited 2 weeks to allow fertilization and oviposition. Because our subject was exposed to both sizes of beans throughout the experiment, we interpreted our results by observing the number of eggs laid on each individual bean. From our observations we calculated the mean, standard deviation, standard error of mean, and for statistical purposes, ran a t-test. We found our results to be statistically significant, therefore we rejected the null hypothesis. From this we can concur that C. maculatus prefers smaller sized beans for oviposition.

Introduction

Oviposition, a commonly used term to describe “laying of eggs”, is broken down into two stages, pre-oviposition and post-oviposition. Pre-oviposition comprises of “all the behaviors and factors involved in the selection of, or attraction to, an oviposition site and oviposition itself” (Downes and Lancaster 2013). Individuals locate suitable sites for their offspring by seeking visual and chemical cues throughout the environment; even the behavior through which these individuals lay their eggs depends on environmental factors. Post-oviposition occurs after the eggs have left the female and involves several different “strategies for ensuring that development of the embryo can proceed” (Downes and Lancaster 2013). Some examples include camouflaging the egg to resemble its site, “devices for attaching eggs to substrates”, and nutrient and gas exchange within the egg (Downes and Lancaster 2013). The site of oviposition is determined by behavioral and environmental cues that increase the probability of the offspring’s survival and the parent’s fitness. This is why the significance of where the organism selects to oviposit his or her offspring is crucial for their offspring’s survival, and his or her fitness.