Biology subjects

Mills, F.

Publications and source records attributed to Mills, F..

3 recordsLinked to original sources

bioRxiv2022

Amygdalostriatal transition zone neurons encode sustained valence to direct conditioned behaviors

To ensure survival, the brain must rapidly identify threats and maintain defensive behaviors for as long as danger is present. The amygdala has been studied as a key site for fear responses, but responses to threat cues in amygdala neurons are largely transient and shorter in duration than defensive responses observed. Here, we present the amygdalostriatal transition zone (ASt) as a missing piece of the circuits mediating fear responses. Using single-nucleus RNA sequencing (snRNA-seq), we demonstrate that the ASt is genetically distinct from adjacent striatal and amygdalar structures. In vivo electrophysiology and calcium imaging reveal that ASt neurons have robust, sustained responses to shock-predicting cues. Further, photostimulation of the ASt is sufficient to drive freezing and avoidance behaviors, and optogenetic inhibition experiments show that Drd2+ ASt neurons are necessary for cue-conditioned fear responses. Our findings establish the ASt as a previously unappreciated yet critical structure for encoding learned associations and directing defensive behaviors.

neuroscience↗

bioRxiv2022

Thalamus sends information about arousal but not valence to the amygdala

RationaleThe basolateral amygdala (BLA) and medial geniculate nucleus of the thalamus (MGN) have both been shown to be necessary for the formation of associative learning. While the role that the BLA plays in this process has long been emphasized, the MGN has been less well-studied and surrounded by debate regarding whether the relay of sensory information is active or passive. ObjectivesWe seek to understand the role the MGN has within the thalamoamgydala circuit in the formation of associative learning. MethodsHere, we use optogenetics to dissect the MGN-BLA circuit and explore the specific subpopulations for evidence of learning and synthesis of information that could impact downstream BLA encoding. We employ various machine learning techniques to investigate function within neural subpopulations. We introduce a novel method to investigate tonic changes across trial-by-trial structure, which offers an alternative approach to traditional trial-averaging techniques. ResultsWe find that the MGN appears to encode arousal but not valence, unlike the BLA which encodes for both. We find that the MGN and the BLA appear to react differently to expected and unexpected outcomes; the BLA biased responses toward reward prediction error and the MGN focused on anticipated punishment. We uncover evidence of tonic changes by visualizing changes across trials during inter-trial intervals (baseline epochs) for a subset of cells. ConclusionWe conclude that the MGN-BLA projector population acts as both filter and transferer of information by relaying information about the salience of cues to the amygdala, but these signals are not valence-specified. PrefaceIn tribute to Nadia Chaudhri, and her discoveries regarding how contexts can modulate the representation of cues in the amygdala (Sciascia et al., 2015), and other mesolimbic circuit components (Chaudhri et al., 2009, 2008; Valyear et al., 2020), here we explore what information processing precedes entry into the basolateral amygdala (BLA) from the thalamus and develop visualization approaches for exploring across-trial temporal dynamics in addition to within-trial population activity.

neuroscience↗

bioRxiv2018

Opinions of 12 to 13-year-olds in Austria and Australia on the worry, cause and imminence of Climate Change

Although we are in the third decade of climate science communication as a discipline, and there is overwhelming scientific consensus and physical evidence for climate change, the general public continues to wrestle with climate change policy and advocacy. Early adolescence (12 to 13 years old) is a critical but under-researched demographic for the formation of attitudes related to climate change. This paper presents opinions on the worry, cause, and imminence of climate change that were collected from n=463 1st year secondary school students (12-13 years old) in public secondary schools in inner-urban centres in Austria and Australia. Overall, 86.83% of eligible respondents agreed that climate change was probably or definitely something we should worry about, 80.33% agreed that climate change was probably or definitely caused by humans, and 83.17% agreed that climate change was probably or definitely something that was happening now. The respondents opinions were also compared to their respective adult population, with Australian 12-13 year olds showing strong positive climate-friendly attitudes, both in comparison to their adult population, and to their Austrian peers. In addition, although the opinions of Austrian 12-13 year olds were quite high, they did not reflect the higher climate-friendly opinions of their adult community. Our results suggest that socio-cultural worldview or socio-cultural cognition theory may not have the influence on this age group as it does on the respective adult population - and, if they are affected, there are attitudes or factors in this age group which resist the opinion-influence from their mature community. These findings are significant as early adolescents may be pivotal in the climate science communication arena and investigating their opinions with regard to climate change may offer an unexplored and under-utilised target for future communication efforts and climate literacy programmes.

scientific communication and education↗