Our aim is to understand how information is processed and computed by neuronal circuits, and relate this to the control of behaviour. We primarily study neuronal circuit operations in the neocortex and retina using state-of-the-art multi-site electrophysiological and optical recording techniques. We have discovered that active dendritic integration in the output neurons of the retina and neocortex underlies behaviourally engaged circuit-level computations. Our ongoing work at the single cell level determines how regenerative activity is generated in and spreads throughout the complex dendritic tree of neurons to control action potential output and, at the network level, the neuromodulatory control of neuronal circuit operations.
We use advanced electrophysiological and optical techniques to mechanistically dissect physiologically engaged computations in the retinal and neocortical micro-circuitry. Pioneering work has revealed that neuronal circuit computations occur in the fine tree-like dendritic arbours of central neurons, a finding that demonstrates that the fine-scale interplay between network connectivity and sub-cellular information processing lies at the heart of brain computations.
Ongoing work in the laboratory is aimed at discovering the circuit elements that drive and control physiologically engaged dendritic information processing. For example, the group’s recent work has demonstrated that active dendritic integration in the output neurons of the neocortex is strongly modulated by the cholinergic system, providing a plausible candidate mechanism for attentional processing. Furthermore, in the retina they are dissecting the functional impact of the co-release of neurotransmitters from interneurons on the control of network computations, in order to better understand visual processing.
Group leader
Professor Stephen Williams
NHMRC Leadership Fellow, Queensland Brain Institute
+61 7 334 66352
srw@uq.edu.au
UQ Researcher Profile
Role of dendritic information processing in visual circuit computations
(2015–2018) NHMRC Project Grant
Freemasons Queensland Senior Research Fellowship in Learning and Memory
(2012–2020) Research Donation Generic
Phototransduction in a marine sponge provides insights into the origin of animal vision
Wong, Eunice, Anggono, Victor, Williams, Stephen R., Degnan, Sandie M. and Degnan, Bernard M. (2022). Phototransduction in a marine sponge provides insights into the origin of animal vision. iScience, 25 (6) 104436, 104436. doi: 10.1016/j.isci.2022.104436
A dendritic substrate for the cholinergic control of neocortical output neurons
Williams, Stephen R. and Fletcher, Lee N. (2019). A dendritic substrate for the cholinergic control of neocortical output neurons. Neuron, 101 (3), 486-499.e4. doi: 10.1016/j.neuron.2018.11.035
Neocortical Topology Governs the Dendritic Integrative Capacity of Layer 5 Pyramidal Neurons
Fletcher, Lee N. and Williams, Stephen R. (2019). Neocortical Topology Governs the Dendritic Integrative Capacity of Layer 5 Pyramidal Neurons. Neuron, 101 (1), 76-90.e4. doi: 10.1016/j.neuron.2018.10.048
Cotel, Florence, Fletcher, Lee N., Kalita-de Croft, Simon, Apergis-Schoute, John and Williams, Stephen R. (2018). Cell class-dependent intracortical connectivity and output dynamics of layer 6 projection neurons of the rat primary visual cortex. Cerebral Cortex, 28 (7), 2340-2350. doi: 10.1093/cercor/bhx134
Brombas, A., Kalita-de Croft, S., Cooper-Williams, E. J. and Williams, S. R. (2017). Dendro-dendritic cholinergic excitation controls dendritic spike initiation in retinal ganglion cells. Nature Communications, 8 (1) 15683, 15683. doi: 10.1038/ncomms15683
Integrating neuroscience and learning: now’s the time
Sah, Pankaj, Fanselow, Michael, Hattie, John, Magsamen, Susan, Mattingley, Jason, Quirk, Gregory and Williams, Stephen (2016) Integrating neuroscience and learning: now’s the time. n p j Science of Learning, 1 . doi:10.1038/npjscilearn.2016.7
Harnett, Mark T, Magee, Jeffrey C and Williams, Stephen R (2015) Distribution and function of HCN channels in the apical dendritic tuft of neocortical pyramidal neurons. Journal of Neuroscience, 35 3: 1024-1037. doi:10.1523/JNEUROSCI.2813-14.2015
Activity-dependent modulation of layer 1 inhibitory neocortical circuits by acetylcholine
Brombas, Arne, Fletcher, Lee N. and Williams, Stephen R. (2014) Activity-dependent modulation of layer 1 inhibitory neocortical circuits by acetylcholine. Journal of Neuroscience, 34 5: 1932-1941. doi:10.1523/JNEUROSCI.4470-13.2014
Sensory-evoked synaptic integration in cerebellar and cerebral cortical neurons
Chadderton, Paul, Schaefer, Andreas T., Williams, Stephen R. and Margrie, Troy W. (2014) Sensory-evoked synaptic integration in cerebellar and cerebral cortical neurons. Nature Reviews Neuroscience, 15 2: 71-83. doi:10.1038/nrn3648
Synchrony and the single neuron
Williams, Stephen R. (2013) Synchrony and the single neuron. Nature Neuroscience, 16 12: 1714-1715. doi:10.1038/nn.3586
Harnett, Mark T., Xu, Ning-Long, Magee, Jeffrey C. and Williams, Stephen R. (2013) Potassium channels control the interaction between active dendritic integration compartments in layer 5 cortical pyramidal neurons. Neuron, 79 3: 516-529. doi:10.1016/j.neuron.2013.06.005
Nonlinear dendritic integration of sensory and motor input during an active sensing task
Xu, Ning-long, Harnett, Mark T., Williams, Stephen R., Huber, Daniel, O'Connor, Daniel H., Svoboda, Karel and Magee, Jeffrey C. (2012) Nonlinear dendritic integration of sensory and motor input during an active sensing task.Nature, 492 7428: 247-251. doi:10.1038/nature11601
Etherington, Sarah J. and Williams, Stephen R. (2011) Postnatal development of intrinsic and synaptic properties transforms signaling in the layer 5 excitatory neural network of the visual cortex. Journal of Neuroscience, 31 26: 9526-9537. doi:10.1523/JNEUROSCI.0458-11.2011
Atkinson, Susan E., Maywood, Elizabeth S., Chesham, Johanna E., Wozny, Christian, Colwell, Christopher S., Hastings, Michael H. and Williams, Stephen R. (2011) Cyclic AMP signaling controls action potential firing rate and molecular circadian pacemaking in the suprachiasmatic nucleus. Journal of Biological Rhythms, 26 3: 210-220. doi:10.1177/0748730411402810
Errors in the measurement of voltage-activated ion channels in cell-attached patch-clamp recordings
Williams, Stephen R. and Wozny, Christian (2011) Errors in the measurement of voltage-activated ion channels in cell-attached patch-clamp recordings. Nature Communications, 2 242: 242-1-242-9. doi:10.1038/ncomms1225
Wozny, Christian and Williams, Stephen R. (2011) Specificity of synaptic connectivity between layer 1 inhibitory interneurons and layer 2/3 pyramidal neurons in the rat neocortex. Cerebral Cortex, 21 8: 1818-1826. doi:10.1093/cercor/bhq257
Neuroscience: The chain reaction of dendritic integration
Williams, Stephen R. and Wozny, Christian (2009) Neuroscience: The chain reaction of dendritic integration. Current Biology, 19 20: R956-R957. doi:10.1016/j.cub.2009.08.031
Postnatal development of dendritic synaptic integration in rat neocortical pyramidal neurons
Atkinson, Susan E. and Williams, Stephen R. (2009) Postnatal development of dendritic synaptic integration in rat neocortical pyramidal neurons. Journal of Neurophysiology, 102 2: 735-751. doi:10.1152/jn.00083.2009
Dendritic synaptic integration in central neurons
Williams, Stephen R. and Atkinson, Susan E. (2008) Dendritic synaptic integration in central neurons. Current Biology, 18 22: R1045-R1047. doi:10.1016/j.cub.2008.08.060
Gating motions underlie AMPA receptor secretion from the endoplasmic reticulum
Penn, Andrew C., Williams, Stephen R . and Greger, Ingo H. (2008) Gating motions underlie AMPA receptor secretion from the endoplasmic reticulum. EMBO Journal, 27 22: 3056-3068. doi:10.1038/emboj.2008.222
Direct measurement of somatic voltage clamp errors in central neurons
Williams, Stephen R. and Mitchell, Simon J. (2008) Direct measurement of somatic voltage clamp errors in central neurons. Nature Neuroscience, 11 7: 790-798. doi:10.1038/nn.2137
Action potential generation requires a high sodium channel density in the axon initial segment
Kole, Maarten H. P ., Ilschner, Susanne U., Kampa, Bjorn M., Williams, Stephen R., Ruben, Peter C. and Stuart, Greg J. (2008) Action potential generation requires a high sodium channel density in the axon initial segment. Nature Neuroscience, 11 2: 178-186. doi:10.1038/nn2040
The back and forth of dendritic plasticity
Williams, Stephen R., Wozny, Christian and Mitchell, Simon J. (2007) The back and forth of dendritic plasticity.Neuron, 56 6: 947-953. doi:10.1016/j.neuron.2007.12.004
Williams, Stephen R. and Atkinson, Susan E. (2007) Pathway-specific use-dependent dynamics of excitatory synaptic transmission in rat intracortical circuits. The Journal of Physiology, 585 3: 759-777. doi:10.1113/jphysiol.2007.138453
Dopamine gates action potential backpropagation in midbrain dopaminergic neurons
Gentet, Luc J. and Williams, Stephen R. (2007) Dopamine gates action potential backpropagation in midbrain dopaminergic neurons. Journal of Neuroscience, 27 8: 1892-1901. doi:10.1523/JNEUROSCI.5234-06.2007
Encoding and decoding of dendritic excitation during active states in pyramidal neurons
Williams, Stephen R. (2005) Encoding and decoding of dendritic excitation during active states in pyramidal neurons.Journal of Neuroscience, 25 25: 5894-5902. doi:10.1523/JNEUROSCI.0502-05.2005
Spatial compartmentalization and functional impact of conductance in pyramidal neurons
Williams, Stephen R. (2004) Spatial compartmentalization and functional impact of conductance in pyramidal neurons. Nature Neuroscience, 7 9: 961-967. doi:10.1038/nn1305
Dependence of EPSP efficacy on synapse location in neocortical pyramidal neurons
Williams, Stephen R. and Stuart, Greg J. (2002) Dependence of EPSP efficacy on synapse location in neocortical pyramidal neurons. Science, 295 5561: 1907-1910. doi:10.1126/science.1067903
Research Areas
- Neuronal circuits
- Control of behaviour
- Dendritic information processing
- Neurotransmitters in the retina
- Visual processing
