The Thalamus as a Low Pass Filter: Filtering at the Cellular Level does Not Equate with Filtering at the Network Level

• Published in: Frontiers in neural circuits 2016-01, Vol.9, p.89-89
• Main Authors: Connelly, William M, Laing, Michael, Errington, Adam C, Crunelli, Vincenzo
• Format: Article
• Language: English
• Subjects: Action Potentials - physiology; Animals; Central nervous system; Cerebral Cortex - physiology; computational neuroscience; Computer Simulation; Excitatory Postsynaptic Potentials - physiology; Information systems; integrate-and-fire neuron; Models, Neurological; neural noise; Neural Pathways - physiology; Neurons; Neurons - physiology; Neuroscience; Neurosciences; Patch-Clamp Techniques; Population; Rats, Wistar; Retina; Retinal Ganglion Cells - physiology; Sensory Neuroscience; Thalamic nuclei; Thalamus; Thalamus - physiology; Tissue Culture Techniques
• ISSN: 1662-5110; 1662-5110
• DOI: 10.3389/fncir.2015.00089

In the mammalian central nervous system, most sensory information passes through primary sensory thalamic nuclei, however the consequence of this remains unclear. Various propositions exist, likening the thalamus to a gate, or a high pass filter. Here, using a simple leaky integrate and fire model based on physiological parameters, we show that the thalamus behaves akin to a low pass filter. Specifically, as individual cells in the thalamus rely on consistent drive to spike, stimuli that is rapidly and continuously changing over time such that it activates sensory cells with different receptive fields are unable to drive thalamic spiking. This means that thalamic encoding is robust to sensory noise, however it induces a lag in sensory representation. Thus, the thalamus stabilizes encoding of sensory information, at the cost of response rate.