Dr Helen Eachus

Supervisor Details

Contact Details

Scientific Background

Research Interests

I am a developmental neurobiologist using zebrafish models to understand how stress modulates brain development and behaviour in the context of health and disease. My research aims to address some long-standing open questions in the field through approaches including comprehensive analysis of stress-induced molecular and behavioural alterations; analysis of the development trajectory of stress-induced changes across the life span; linking molecular mechanisms with behaviour; and screening of potential therapeutics for stress-related disorders. My research uses techniques including brain imaging, behavioural analysis, sequencing, stress hormone analysis.

Current research topics include:

Identification of molecular mechanisms underlying brain plasticity following early life stress
Investigation of early life stress-induced senescence and accelerated brain aging
Mechanisms underlying neuronal development and stress susceptibility in zebrafish models of humans psychiatric disease

Supervision Style

In three words or phrases: supportive, mentorship-focused, goal-oriented.

Provision of Training

I prioritise providing comprehensive technical training during the initial stages of your PhD, ensuring you have a solid foundation and the necessary skills to succeed. As you progress, you will take more ownership of your research by independently identifying and adapting methodologies, fostering your growth and confidence as a researcher.

Progression Monitoring and Management

Together we will establish clear milestones and goals that we will discuss and agree upon in advance. If adequate progress is not made, we will collaboratively develop a plan of action to address any challenges and keep you on track towards your goals.

Communication

Communication within the team primarily occurs through email and a dedicated MS Teams channel for quick responses. While I expect you to stay engaged with team communications, responses outside of working hours are not required to ensure a healthy work-life balance.

PhD Students can expect scheduled meetings with me:

In a group meeting

At least once a week

In year 1 of PhD study

At least once a week

In year 2 of PhD study

At least once a fortnight

In year 3 of PhD study

At least once a month

These meetings will be a mixture of face to face, via video chat or telephone, and I have an open-door policy, though my pattern of being contactable for an instant response is not predictable.

Working Pattern

The timing of work in my lab is completely flexible, and (other than attending pre-arranged meetings), I expect students to manage their own time.

Notice Period for Feedback

I need at least 1 week’s notice to provide feedback on written work of up to 5000 words.

MIBTP Project Details

Current Projects (2025-26)

Primary supervisor for:

From adaptation to allostatic overload: understanding the tipping point in stress-induced neuroplasticity

See the PhD Opportunities section to see if this project is currently open for applications via MIBTP.

Please Note: The main page lists projects via BBSRC Research Theme(s) quoted and then relevant Topic(s).

From adaptation to allostatic overload: understanding the tipping point in stress-induced neuroplasticity

Secondary Supervisor(s): Dr Stuart Greenhill

University of Registration: Aston University

BBSRC Research Themes: Understanding the Rules of Life (Neuroscience and Behaviour)

Project Outline

Stress is an essential part of life, prompting physiological and behavioural adaptations that are critical for survival and resilience. When stress is transient, these responses are adaptive, promoting coping mechanisms and maintaining homeostasis. However, chronic stress exposure can overwhelm these adaptive systems, leading to what is termed allostatic overload, which is associated with detrimental changes in brain function and structure. Understanding the mechanisms that underlie the transition from adaptive to maladaptive states in the brain is crucial for identifying targets for interventions to mitigate stress-related pathologies.

The hypothalamus is a central regulator of stress responses, coordinating neuroendocrine, autonomic, and behavioural outputs. Our recent research suggests that neurogenesis in the hypothalamus, the process by which new neurons are generated, is dynamically regulated by stress. We used an optogenetic zebrafish model with which we can manipulate stress hormone levels using blue light exposure. We found that in the short-term, acute stress enhances neurogenesis in the hypothalamus, meanwhile in the long-term, chronic stress has the opposite effect, leading to impaired neuroplasticity. However, the molecular and physiological mechanisms that define the tipping point from adaptive to maladaptive neurogenesis remain largely unknown.

Aims

This project aims to identify the molecular and cellular determinants of stress-induced changes in hypothalamic neurogenesis and their functional implications. Using the zebrafish model, which allows for non-invasive imaging and precise genetic manipulation, we will investigate:

Longitudinal analysis of molecular and cellular features associated with stress-induced altered neurogenesis in the hypothalamus. This will involve in vivo tracking of neural stem cell activity, proliferation, and differentiation.

Identification of functional correlates of stress-induced altered neurogenesis. By performing in vivo electrophysiological recordings, we will examine how stress impacts the hypothalamic neural circuitry and corresponding physiological outputs.

Manipulation of stress-responsive molecules to prevent the onset of allostatic overload. We will employ pharmacological and genetic tools to modulate candidate pathways and evaluate their capacity to restore adaptive neurogenesis and prevent maladaptive outcomes.

Methods

The project will employ a combination of in vivo imaging, electrophysiological recordings, and molecular biology techniques to address the research aims:

Live Imaging: Using transgenic zebrafish lines expressing fluorescent reporters in neural stem cells, we will conduct time-lapse imaging to track changes in neurogenesis in response to stress.

Electrophysiology: Whole-cell patch-clamp recordings in live zebrafish will be used to assess alterations in hypothalamic neural activity associated with stress exposure.

Pharmacological and Genetic Manipulations: Candidate stress-responsive signalling pathways will be modulated using CRISPR/Cas9 and chemical inhibitors to dissect their role in the transition from adaptive to maladaptive neuroplasticity.

Significance

This research will provide new insights into the molecular and cellular basis of the brain’s response to stress, defining key mechanisms that contribute to the breakdown of adaptive neurogenesis and the onset of allostatic overload. Ultimately, these findings may lead to the development of novel strategies to promote resilience and prevent stress-related disorders.

References

Eachus H, et al (2024). Elevated glucocorticoid alters the developmental dynamics of hypothalamic neurogenesis. Communications Biology. https://doi.org/10.1038/s42003-024-06060-5.

Eachus H & Ryu S (2024). Early Life Stress: from Adaptive Plasticity to Allostatic Overload. Invited Review for Special Issue on Developmental Plasticity. Journal of Experimental Biology. https://doi.org/10.1242/jeb.246128.