Overview
I am an MRC Research Fellow with interests in complex dynamical processes in neuroscience and neuroendocrinology. Using a multidisciplinary approach, combining predictive mathematical modelling and analysis with experimental biology, I am currently focused on understanding how the hypothalamic-pituitary-adrenal (HPA) axis regulates the pulsatile secretion of vital glucocorticoid hormones, and why the dynamics of this system changes in different physiological and pathological conditions. This is an important question to address because pulsatile patterns of glucocorticoids are important for the dynamic regulation of gene expression, as well as for more rapid non-genomic effects of glucocorticoids on neuronal function (e.g. synaptic transmission) and behavioural activity (e.g. stress responsiveness and aggression).
Publications
Copyright Notice: Any articles made available for download are for personal use only. Any other use requires prior permission of the author and the copyright holder.
| 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2010 |
2023
- Marinelli I, Walker JJ, Seneviratne U, D'Souza W, Cook MJ, Anderson C, Bagshaw AP, Lightman SL, Woldman W, Terry JR. (2023) Circadian distribution of epileptiform discharges in epilepsy: Candidate mechanisms of variability, PLoS Comput Biol, volume 19, no. 10, DOI:10.1371/journal.pcbi.1010508. [PDF]
2022
- Walker JJ, Romanò N. (2022) Fast dynamics in the HPA axis: Insight from mathematical and experimental studies, Current Opinion in Endocrine and Metabolic Research, volume 27, DOI:10.1016/j.coemr.2022.100403.
- Galvis D, Zavala E, Walker JJ, Upton T, Lightman SL, Angelini GD, Evans J, Rogers CA, Phillips K, Gibbison B. (2022) Modelling the dynamic interaction of systemic inflammation and the hypothalamic-pituitary-adrenal (HPA) axis during and after cardiac surgery, J R Soc Interface, volume 19, no. 189, DOI:10.1098/rsif.2021.0925. [PDF]
2021
- Smith LIF, Zhao Z, Walker J, Lightman S, Spiga F. (2021) Activation and expression of endogenous CREB-regulated transcription coactivators (CRTC) 1, 2 and 3 in the rat adrenal gland, Journal of Neuroendocrinology, volume 33, no. 1, DOI:10.1111/jne.12920.
2020
- Zavala E, Voliotis M, Zerenner T, Tabak J, Walker JJ, Li XF, Terry JR, Lightman SL, O’Byrne K, Tsaneva-Atanasova K. (2020) Dynamic Hormone Control of Stress and Fertility, Frontiers in Physiology, volume 11, pages 1457-1457, DOI:10.3389/fphys.2020.598845. [PDF]
- Campos P, Walker JJ, Mollard P. (2020) Diving into the brain: deep-brain imaging techniques in conscious animals, J Endocrinol, volume 246, no. 2, pages R33-R50, DOI:10.1530/JOE-20-0028. [PDF]
- Richards DM, Walker JJ, Tabak J. (2020) Ion channel noise shapes the electrical activity of endocrine cells, PLoS Comput Biol, volume 16, no. 4, DOI:10.1371/journal.pcbi.1007769. [PDF]
2019
- Tilston TW, Brown RD, Wateridge MJ, Arms-Williams B, Walker JJ, Sun Y, Wells T. (2019) A Novel Automated System Yields Reproducible Temporal Feeding Patterns in Laboratory Rodents, J Nutr, volume 149, no. 9, pages 1674-1684, DOI:10.1093/jn/nxz116. [PDF]
2018
- Stirrat LI, Walker JJ, Stryjakowska K, Jones N, Homer NZM, Andrew R, Norman JE, Lightman SL, Reynolds RM. (2018) Pulsatility of glucocorticoid hormones in pregnancy: Changes with gestation and obesity, Clin Endocrinol (Oxf), volume 88, no. 4, pages 592-600, DOI:10.1111/cen.13548. [PDF]
2017
- Spiga F, Zavala E, Walker JJ, Zhao Z, Terry JR, Lightman SL. (2017) Dynamic responses of the adrenal steroidogenic regulatory network, Proc Natl Acad Sci U S A, volume 114, no. 31, pages E6466-E6474, DOI:10.1073/pnas.1703779114. [PDF]
- Romanò N, McClafferty H, Walker JJ, Le Tissier P, Shipston MJ. (2017) Heterogeneity of Calcium Responses to Secretagogues in Corticotrophs From Male Rats, Endocrinology, volume 158, no. 6, pages 1849-1858, DOI:10.1210/en.2017-00107. [PDF]
2016
- Stirrat L, Walker J, Norman J, Lightman S, Walker B, Reynolds R. (2016) Role of cortisol ultradian pulsatility in human pregnancy: a case-control study, The Lancet, volume 387, DOI:10.1016/s0140-6736(16)00480-3.
- Terry JR, Walker JJ, Spiga F, Lightman SL. (2016) Dynamics of the HPA axis: A systems modelling approach, Computational Neuroendocrinology, Wiley, 252-283.
2015
- Gibbison B, Spiga F, Walker JJ, Russell GM, Stevenson K, Kershaw Y, Zhao Z, Henley D, Angelini GD, Lightman SL. (2015) Dynamic pituitary-adrenal interactions in response to cardiac surgery, United States, Crit Care Med, volume 43, no. 4, pages 791-800, DOI:10.1097/CCM.0000000000000773. [PDF]
- Walker JJ, Spiga F, Gupta R, Zhao Z, Lightman SL, Terry JR. (2015) Rapid intra-adrenal feedback regulation of glucocorticoid synthesis, J R Soc Interface, volume 12, no. 102, DOI:10.1098/rsif.2014.0875. [PDF]
2014
- Gibbison B, Walker J, Russell G, Stevenson K, Kershaw Y, Asimakopoulos G, Angelini G, Lightman S. (2014) Cardiac surgery alters the sensitivity of the dynamic interaction between the pituitary and adrenal glands, Critical Care, volume 18, no. Suppl 1, DOI:10.1186/cc13625.
- Spiga F, Walker JJ, Terry JR, Lightman SL. (2014) HPA Axis - Rhythms, Comprehensive Physiology, no. 4, pages 1273-1298, DOI:10.1002/cphy.c140003. [PDF]
- Spiga F, Walker JJ, Terry JR, Lightman SL. (2014) HPA axis-rhythms, Compr Physiol, volume 4, no. 3, pages 1273-1298, DOI:10.1002/cphy.c140003. [PDF]
2013
- Park SY, Walker JJ, Johnson NW, Zhao Z, Lightman SL, Spiga F. (2013) Constant light disrupts the circadian rhythm of steroidogenic proteins in the rat adrenal gland, Mol Cell Endocrinol, volume 371, no. 1-2, pages 114-123, DOI:10.1016/j.mce.2012.11.010. [PDF]
2012
- Krauskopf B, Walker JJ. (2012) Bifurcation Study of a Semiconductor Laser with Saturable Absorber and Delayed Optical Feedback, pages 161-181, DOI:10.1002/9783527639823.ch7.
- Waite EJ, McKenna M, Kershaw Y, Walker JJ, Cho K, Piggins HD, Lightman SL. (2012) Ultradian corticosterone secretion is maintained in the absence of circadian cues, Eur J Neurosci, volume 36, no. 8, pages 3142-3150, DOI:10.1111/j.1460-9568.2012.08213.x. [PDF]
- Walker JJ, Spiga F, Waite E, Zhao Z, Kershaw Y, Terry JR, Lightman SL. (2012) The origin of glucocorticoid hormone oscillations, PLoS Biol, volume 10, no. 6, DOI:10.1371/journal.pbio.1001341. [PDF]
- Rankin J, Walker JJ, Windle R, Lightman SL, Terry JR. (2012) Characterizing dynamic interactions between ultradian glucocorticoid rhythmicity and acute stress using the phase response curve, PLoS One, volume 7, no. 2, DOI:10.1371/journal.pone.0030978. [PDF]
2010
- Walker JJ, Terry JR, Tsaneva-Atanasova K, Armstrong SP, McArdle CA, Lightman SL. (2010) Encoding and decoding mechanisms of pulsatile hormone secretion, J Neuroendocrinol, volume 22, no. 12, pages 1226-1238, DOI:10.1111/j.1365-2826.2010.02087.x. [PDF]
- Walker JJ, Terry JR, Lightman SL. (2010) Origin of ultradian pulsatility in the hypothalamic-pituitary-adrenal axis, Proc Biol Sci, volume 277, no. 1688, pages 1627-1633, DOI:10.1098/rspb.2009.2148. [PDF]
