Updated December 7th, 2021
Research Spotlight
Reduced Dopamine Signaling Impacts Pyramidal Neuron Excitability in Mouse Motor Cortex
Selective loss of dopamine-producing neurons leads to voluntary movement dysfunction as observed in patients with Parkinson’s disease. The primary motor cortex (M1) is a critical area for movement control, however very little is known about how reduced dopamine signaling impacts the region on a cellular level. Swanson, Semaan and Maffei report that diminished dopamine signaling alters the excitability of M1 pyramidal neurons in a mouse model of Parkinson’s disease. Furthermore, these effects were dependent on each cell’s laminar location and in some manipulations relied on shifts in synaptic transmission. Results provide neural mechanisms that may underlie reports of altered M1 activity in patients and emphasize the importance of exploring M1 as a critical region in the study of Parkinson’s disease.
Processes of intentional forgetting in human participants are often times studied with the paradigm of item-method directed forgetting. In their research, Scholz et al. demonstrated that theta oscillations in the human EEG were elevated following an instruction to remember a preceding information and alpha oscillations were elevated following the instruction to forget an information. These oscillatory effects were found to be mediated by the time given to process the specific memory instruction. Thereby, this research suggests, that item-method directed forgetting is best explained by a combination of rehearsal and inhibitory control.
Damage to bone and cartilage in the knee joint causes pain and is a risk factor for development of osteoarthritis. Large animal models like sheep share a more similar joint anatomy to humans than rodents, thus making them a good model for studying joint injury and disease. However, studies to date using sheep have largely focused on bone and cartilage repair after injury. Here, Chakrabarti et al. show that pain-sensing nerves supplying injured joints in sheep become more excitable, thus showing that sheep are a good model for studying mechanisms of joint pain.
High Behavioral Variability Mediated by Altered Neuronal Excitability in auts2 Mutant Zebrafish
AUTS2 is a protein that controls what other proteins are to be made in nerve cells during the development of the nervous system. Because of this crucial role, mutations in AUTS2 can lead to neurological disorders including Autism Spectrum Disorders (ASDs). But, the link between AUTS2 and behavior is poorly understood. Jha et al. show that in larval zebrafish, mutations in auts2a (fish version of AUTS2), can impair even normally robust behaviors because of changes in how neurons fire action potentials.