Brian Mulloney
Distinguished Research Professor of Biological Sciences
bcmulloney@ucdavis.edu
Neurobiology, Physiology and Behavior
Office
1155 Life Sciences
(530) 752-1110
Lab
(530) 752-1562
Degrees:
1969
PhD
University of California, Berkeley
(Zoology)
1967
MA
University of California, Berkeley
(Zoology)
1963
BS
McGill University
(Zoology and Chemistry)
Research Interests:
I am interested in how an animal's nervous system produces the overt behaviors that we observe. My research concentrates on how the central nervous system of arthropods, particularly crayfish, works. The behaviors of these animals are complex, but their nervous systems have a structural elegance that makes the challenge of understanding these behaviors in cellular terms achievable. In answering questions about the neural basis of behaviors in these animals, we also provide probable explanations of complex behaviors in other animals, including vertebrates.
Some time ago, we began to analyze the central mechanisms that cause the swimmerets of crayfish to produce coordinated cycles of power-strokes and return-strokes whenever the animal swims forward. We demonstrated that each limb has its own module of neurons that can operate independently. This means that the normal coordination of movements of different limbs is imposed on these modules by a separate circuit of coordinating interneurons, and that we can study the organization of a module and of the coordinating circuit as separate problems.
My strategy is to combine electrophysiological experiments with computational analysis of the hypotheses these experiments generate. We have identified a small set of nonspiking local interneurons that are key components of each module. We have developed a minimal cellular model of the organization of a module, and are starting to test it experimentally. We have also described three types of intersegmental coordinating interneurons that are necessary and sufficient for normal intersegmental coordination, and described how these interneurons respond to changes in excitation of the system. We have developed a cellular model of the circuit formed by these interneurons. This model has dynamics similar to the dynamics of the real system, and that predicts the connections these interneurons make within their target modules.
Neural control of locomotion; pattern-generation and circuit dynamics; neural basis of decision-making; computational neuroscience
Awards:
Fellow of the Japan Society for Promotion of Science (1995)
Councillor of the International Society for Neuroethology (1992-1998)
Alexander v. Humboldt Research Fellowship
A.P. Sloan Foundation Research Fellow
Fellow of AAAS
Department and Center Affiliations:
Center for Neuroscience
Professional Societies:
Society for Neuroscience
International Society for Neuroethology
AAAS (Fellow)
American Physiological Society
Organization for Computational Neurosciences
CBS Graduate Group Affiliations:
Neuroscience
Publications:
Last updated 5/1/2013
Smarandache-Wellmann CR, C Weller, TM Wright Jr. and B Mulloney (2013) Five types of non-spiking interneurons in the local pattern-generating circuits of the crayfish swimmeret system. J Neurophysiol. doi:10.1152/jn.00079.2013
Mulloney, B. and C.R. Smarandache-Wellmann (2012) Neurobiology of the crustacean swimmeret system. Prog. Neurobiol. doi:10.1016/j.pneurobio.2012.01.002
Mulloney, B and CR Smarandache (2010) Fifty years of CPGs: two neuroethological papers that shaped the course of neuroscience. Frontiers in Behavioral Neuroscience 4 (45): 1-8.
Smarandache, C.R., W.M. Hall, and B. Mulloney (2009) Coordination of rhythmic motor activity by gradients of synaptic strength in a neural circuit that couples modular neural oscillators. J Neurosci. 29: 9351-9360.
Tschuluun N, WM Hall, and B. mulloney (2009) State-changes in the swimmeret system: a neural circuit that drives locomotion. J. Exp. Biol. 212:3605-3611.
Hedrick, AV, M Hisada, and B Mulloney (2007) Tama-kugel: Hardware and software for measuring direction, distance, and velocity of locomotion by insects. J. Neurosci. Methods 164: 86-92.
Brian Mulloney and Wendy M Hall (2007)
Not by spikes alone: Responses of coordinating neurons and the swimmeret system to local differences in excitation.
J Neurophysiol 97:436-450.
Mulloney B and Hall WM (2007) Local and intersegmental interactions of coordinating neurons and local circuits in the swimmeret system. J Neurophysiol. 98: 405-413.
Mulloney B, Harness PI, Hall WM (2006) Bursts of information: coordinating interneurons encode multiple parameters of a periodic motor pattern. J Neurophysiol 95:850-861.
Mulloney B (2005) A method to measure the strength of multi-unit bursts of action-potentials. J Neurosci Meth 146:98-105.
Mulloney B (2003) During fictive locomotion, graded synaptic currents drive bursts of impulses in swimmeret motor neurons. J. Neurosci. 23:5953-5962.
Mulloney B and WM Hall (2003) Local commissural interneurons integrate information from intersegmental coordinating interneurons. J. Comp. Neurol. 466: 366-376.
Jones SR, B Mulloney, TJ Kapper, and N Kopell (2003) Coordination of cellular pattern-generating circuits that control limb movements: The sources of stable differences in intersegmental phase. J. Neurosci. 23: 3457-3468.
Mulloney B, N Tschuluun, and WM Hall (2003) Architectonics of crayfish ganglia. Microscopy Res. and Tech. 60: 253-265.
Tschuluun N, WM Hall, and B Mulloney (2001) Limb movements during
locomotion: Tests of a model of an intersegmental coordinating
circuit. J Neurosci 21: 7859-7869
Nakagawa H, and B Mulloney (2001) Local specifications of relative
strengths of synapses between different abdominal stretch-receptor
axons and their common target neurons. J. Neurosci. 21:1645-1655
Mulloney, B and WM Hall (2000) Functional organization of crayfish
abdominal ganglia: III. Swimmeret motor neurons. J. Comp. Neurol.
419: 233-243
Namba, H. and B. Mulloney (1999) Coordination of limb movements: Three
types of intersegmental interneurons in the swimmeret system, and
their responses to changes in excitation. J Neurophysiol. 81:2437-2450
Skinner FK and B Mulloney (1998) Intersegmental coordination of limb
movements during locomotion: mathematical models predict circuits that
drive swimmeret beating. J Neurosci. 18:3831-3842
Laboratory Personnel:
1155 LSA
People in the Mulloney Lab: Michael Wright, Cynthia Weller and Brian Mulloney
Teaching Interests:
Experimental electrophysiology, nonlinear
dynamics of neural circuits, computational
neurobiology, and practical aspects of a career in
biological research.
Courses:
NPB
100
Neurobiology
Winter
NPB
160
Molecular and Cellular Neurobiology
Spring