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Manuel Castro-Alamancos

Manuel Castro-Alamancos, PhD


Department: Neurobiology & Anatomy


  • PhD - University Complutense/Cajal Institute of Neurobiology
  • Postdoctoral Fellowship - Brown University

Dr. Castro-Alamancos is a professor in the Department of Neurobiology & Anatomy at Drexel University College of Medicine.

Research Overview

Manuel Castro-Alamancos, PhD, is interested in understanding how neuronal circuits generate behavior. His work studies brainstem, midbrain, thalamic and cortical circuits responsible for sensory information processing and motor output during behavior. A major interest is to reveal the activity of these neural circuits during transitions between behavioral states and how dynamic changes in neural circuits mediate changes in behavior.


Research of Manuel Castro-Alamancos

The goal of our laboratory is to elucidate the synaptic, cellular and network mechanisms responsible for the emergence of neural activities that underlie normal and abnormal behaviors. The laboratory currently focuses on two projects. One project is studying the mechanisms involved in the regulation of sensory information during different behavioral states. These studies attempt to define 1) the synaptic, cellular and network properties of brainstem and forebrain neural circuits that process sensory information, 2) how those circuits dynamically change their activity and responsiveness during different levels of arousal and attention to allow information processing, 3) the mechanisms by which the significance of attended sensory stimuli is modified through associative learning, and 4) how and where that information is stored. A second project studies how those same neural circuits generate synchronized oscillatory activities related to normal (e.g. sleep) and abnormal (e.g. epilepsy) behavioral states. One aspect of this work is defining the mechanisms that control abnormal motor output related to seizures and myoclonus. These projects are accomplished using a multidisciplinary approach that spans cellular, systems and behavioral neurophysiology.

Research of Manuel Castro-Alamancos

Understanding how the brain acquires, analyzes, stores and retrieves sensory information is one of the most compelling challenges in neuroscience. Central to sensory information processing, are neural networks that interconnect brainstem, thalamus and neocortex. Understating how a neural network operates requires intimate knowledge of the intrinsic membrane properties of the cells forming the network, and particularly of the synaptic connections between those cells. A major effort in our lab is devoted to understanding the organization and response properties of synaptic connections made by cells in brainstem, midbrain, thalamic and cortical neural networks engaged in sensory information processing.  

Rather than being static, these network connections are highly dynamic and modifiable on a moment to moment basis. In fact, the efficacy of the connections and the intrinsic activity of these networks are transformed during different behavioral states. What mechanisms are responsible for producing these transformations? The underlying premise of this work is that the properties of the network connections are differentially regulated via the effects of neuromodulators released by certain brainstem nuclei as behavioral contingencies demand. In other words, neuromodulators change the properties of these pathways during behavior to allow effective information processing. For example, work in our lab has demonstrated that the temporal and spatial properties of thalamocortical cell receptive fields are modified by the level of arousal, and this is due to neuromodulators that are released in the thalamus during arousal. This means that the thalamus acts like a state-dependent gate that filters sensory information depending on behavioral demands.

Research of Manuel Castro-Alamancos

During attentive states, sensory information is rapidly analyzed and evaluated. Some stimuli are considered irrelevant and ignored, while others have greater significance because of prior association with other stimuli. An important issue is to understand how sensory neural networks change the significance of a particular stimulus so that it can later be detected in that context. For example, an initially neutral stimulus can acquire other significance through association with an aversive event. Are there specialized neural networks to detect and respond to such significant stimuli? Ongoing work in our lab is deciphering the neural networks that detect significant sensory stimuli so that they can produce appropriate behavioral outputs. Such studies combine inactivation of specific cell populations and the monitoring of cell activity during performance of instrumental conditioning tasks, in which subjects learn to fear initially neutral stimuli. The goal of these studies is to decipher the neural networks that serve to detect and interpret a sensory stimulus as significant during behavior.

The knowledge gained about the organization and normal operations of neural networks provides an excellent platform to study how these circuits may go awry during illness. For example, during epilepsy, the activities generated by these circuits may become corrupt and uncontrollable leading to seizures. A parallel effort in our lab is unraveling how neural circuits in neocortex and thalamus are responsible for generating certain forms of seizure activity. A major finding has been that different areas of neocortex, that are side by side, have exceedingly different propensities to generate epileptic discharges. Current work is trying to unravel why such disparate activities emerge from seemingly similar neural networks. Understanding what provides protection to certain cortical areas may help develop better treatments for controlling epileptic discharges.

Research of Manuel Castro-Alamancos

Research Interests

Dynamics of thalamo-cortico-thalamic synaptic networks


Recent Selected Publications

"Synaptic cooperativity regulates persistent network activity in neocortex."
Favero M, Castro-Alamancos MA.
J Neurosci. Feb 13;33(7):3151-63, 2013.

"The motor cortex: a network tuned to 7-14 Hz."
Castro-Alamancos MA.
Front Neural Circuits. Feb 21;7:21, 2013.

"The state of somatosensory cortex during neuromodulation."
Favero M, Varghese G, Castro-Alamancos MA.
J Neurophysiol. Aug;108(4):1010-24, 2012.

"Superior colliculus cells sensitive to active touch and texture during whisking."
Bezdudnaya T, Castro-Alamancos MA.
J Neurophysiol. Jul;106(1):332-46 2011.

"Effects of cortical activation on sensory responses in barrel cortex.
Hirata A, Castro-Alamancos MA.
J Neurophysiol. Apr;105(4):1495-505, 2011.

"Behavioral state dependency of neural activity and sensory (whisker) responses in superior colliculus."
Cohen JD, Castro-Alamancos MA.
J Neurophysiol. Sep;104(3):1661-72, 2010.

"Neural correlates of active avoidance behavior in superior colliculus."
Cohen JD, Castro-Alamancos MA.
J Neurosci. Jun 23;30(25):8502-11, 2010.

"Neocortex network activation and deactivation states controlled by the thalamus."
Hirata A, Castro-Alamancos MA.
J Neurophysiol. Mar;103(3):1147-57, 2010.

"Detection of low salience whisker stimuli requires synergy of tectal and thalamic sensory relays."
Cohen JD, Castro-Alamancos MA.
J Neurosci. Feb 10;30(6):2245-56, 2010.

"Cortical up and activated states: implications for sensory information processing."
Castro-Alamancos MA.
Neuroscientist. Dec;15(6):625-34, 2009.

"Impact of persistent cortical activity (up States) on intracortical and thalamocortical synaptic inputs."
Rigas P, Castro-Alamancos MA.
J Neurophysiol. Jul;102(1):119-31, 2009.

"Influence of subcortical inhibition on barrel cortex receptive fields."
Hirata A, Aguilar J, Castro-Alamancos MA.
J Neurophysiol. Jul;102(1):437-50, 2009.

"Vibrissa sensation in superior colliculus: wide-field sensitivity and state-dependent cortical feedback"
Cohen JD, Hirata A and Castro-Alamancos MA
Journal of Neuroscience 28, 11205-11220, 2008.

"Cortical transformation of wide-field (multiwhisker) sensory responses"
Hirata A, Castro-Alamancos MA
Journal of Neurophysiology 100, 358-370, 2008.

"Early sensory pathways for detection of fearful conditioned stimuli: tectal and thalamic relays"
Cohen JD and Castro-Alamancos MA
Journal of Neuroscience 27, 7762-7776, 2007.

"Thalamocortical Up states: differential effects of intrinsic and extrinsic cortical inputs on persistent activity"
Rigas P and Castro-Alamancos MA
Journal of Neuroscience 27, 4261-4272, 2007.

"Noradrenergic activation amplifies top down and bottom up signal to noise ratios in sensory thalamus"
Hirata A, Aguilar J and Castro-Alamancos MA
Journal of Neuroscience 26, 4426-4436, 2006.

"Spatiotemporal gating of sensory inputs in thalamus during quiescent and activated states"
Aguilar JR, Castro-Alamancos MA
Journal of Neuroscience 25, 2479-2491, 2005.

"Skilled motor learning does not enhance long-term depression in the motor cortex in vivo"
Cohen JD and Castro-Alamancos MA
Journal of Neurophysiology 93, 1486-1497, 2005.

"Dynamics of sensory thalamocortical synaptic networks during information processing states"
Castro-Alamancos MA
Progress in Neurobiology 74, 213-247, 2004.

"Absence of rapid sensory adaptation in neocortex during information processing states."
Castro-Alamancos MA
Neuron 41, 455-464, 2004.

Contact Information

Research Office

Department of Neurobiology & Anatomy
2900 W. Queen Lane
Philadelphia, PA 19129
Phone: 215-991-8287
Fax: 215-843-9082