Choose the three animal phyla that you think best represent

Choose the three animal phyla that you think best represent stages in the evolution of the nervous system of animals. Describe the nervous system structure of each and why you chose them. Then explain how and why you expect each to perform when tested with the following neuro-active molecules: caffeine, epinephrin, and GABA. How will the tests with the molecule inform your understanding of the evolution of nervous systems?

This is conceptual and opinion questions. There is no exact answer but I want to get answer of this.

Solution

The three animal phyla that best represent stages in the evolution of the nervous system of animals are animals belongs to primitive bilateria, Cnidaria and Ctenophora since these are often referred as Epitheliozoa. These animals often diversified from primitive sponges where primitive neuronal system has developed already. The nervous system present in these phyla have no complex brain structures but have neural canals and long single neuronal cells to transmit synaptic responses to muscle cells. The long neuronal cells are completely single celled so that a better model to examine motor effects for cutting -edge research for example in Caenobacter elegans. Prior to these animal phyla, species belongs to arthropods, annelids often belongs to protostomes possess simple neuronal system with no brain structure later evolution of highly developed vertebrates with complex CNS, brain often deuterostomes phylogenetically evoluted. The neuro-active molecules can describe the efficient neuronal activity for example, caeffine is going to act on the ATP receptors & produces excitatory responses whereas epinephrine is going to act on adrenergic receptors finally exert G-protein coupled receptors-mediated excitatory signaling mechanism. The GABA is a inhibitory neurotransmitters so that it is going to produce inhibitory responses on the neurons. These molecules are going to produce differential effects on single-neuronal cells to synaptic plasticity finally active on multi-cellular activity

According to Hebbian theory, explains the concept of neuronal adaptation & neuronal evolution regarding learning process and explains the concept of synaptic plasticity based on these epinephrine, GABA action. The learning process depends on the synaptic plasticity, which makes lasting changes in synaptic transmission efficiency of neurons; the information is stored in these modified synapses and retrieved whenever necessary by activating these synapses. According to Hebb’s theory, if two neurons are active at a time, the synapse between these neurons is strengthened, this is known as Hebb’s synapse.