Research Interests

My research aims to identify the neural basis of long-term memory and to understand the contribution of specific brain regions in the acquisition, storage and retrieval of memories. I am particularly interested in the role of the medial temporal lobe structures (specifically the hippocampus) and the basal ganglia in learning and memory. In order to assess the roles of these brain regions in memory, I use a comparative approach integrating research from the human, monkey, bird and rodent literatures. My recent work has focused on using animal models (rodents) to understand the temporal dynamics of long-term object recognition memory and spatial memory. My studies have focused on the effects of hippocampal damage on both anterograde and retrograde memory. The techniques I employ enable me to either permanently (using excitotoxic, radiofrequency, or aspiration lesions) or transiently (by acute or chronic administration of drugs)disrupt a particular brain region in order to assess the effect on memory. Recent collaborations include assessing the role of adult neurogenesis in the dentate gyrus in learning and memory; investigating the role of the perirhinal cortex in perception, and contributing surgical expertise to studies investigating the function of the dorsal lateral geniculate nucleus and superior colliculus.

Publications

Clark, R.E. Broadbent, N.J., & Squire, L.R. (2007). Large lesions of the hippocampus prevent the expression of memory: findings with a novel modification of the watermaze. Journal of Neuroscience, 27: 6647-6654.

Broadbent, N.J., & Squire, L.R., & Clark, R.E. (2007). Rats depend on habit memory for discrimination learning and retention. Learning and Memory. 14, 145-151.

Broadbent, N.J., & Squire, L.R., & Clark, R.E. (2006). Reversible hippocampal lesions disrupt water maze performance during both recent and remote memory tests. Learning and Memory, 13, 187-191.

Clark, R.E. Broadbent, N.J., & Squire, L.R. (2005). Impaired remote spatial memory after hippocampal lesions despite extensive training beginning early in life. Hippocampus, 15, 340-346

Clark, R.E. Broadbent, N.J., & Squire, L.R. (2005). The hippocampus and remote spatial memory in rats. Hippocampus, 15, 260-272.

Broadbent, N.J., Squire, L.R., and Clark, R.E. (2004). Spatial memory, recognition memory and the hippocampus. Proceedings of the National Academy of Sciences, U.S.A., 14515-14520.

Levy, D.A., Manns, J.R., Hopkins, R.O., Gold, J.J., Broadbent, N.J., & Squire, L.R. (2004). Impaired visual and odor recognition memory span in patients with hippocampal lesions. Learning and Memory, 10, 531-536.

Clark, R.E. Broadbent, N.J., Zola, S., & Squire, L.R. (2002). Anterograde amnesia and temporally-graded retrograde amnesia for a nonspatial memory task following lesions of the hippocampus and subiculum. Journal of Neuroscience, 22(11), 4663-4669.

Colombo, M., Broadbent, N.J., Taylor, C., & Frost, N. (2001). The role of the hippocampus in orientation in space and time in pigeons. Brain Research, 919, 292-301.

Colombo, M., & Broadbent, N. (2000). Is the avian hippocampus a functional homologue of the mammalian hippocampus? Neuroscience and Biobehavioral Reviews, 24, 645-484

Broadbent, N. J., & Colombo, M. (2000). Visual and spatial discrimination behavior following hippocampal lesions in pigeons. Psychobiology, 28(4), 463-475.

Broadbent, N., Gallagher, S., & Colombo, M. (1999). Hippocampal lesions and negative patterning in pigeons. Psychobiology, 21(1), 51-56.

Colombo, M., Cawley, S., & Broadbent, N. (1997). The effects of hippocampal and area parahippocampalis lesions in pigeons. II. Concurrent discrimination and spatial memory. Quarterly Journal of Experimental Psychology, 50B, 172-189.

Curriculum Vitae

A. Education

Doctor of Philosophy, University of Otago, Dunedin, New Zealand, 2000

BSc (Honors, 1st Class), University of Otago, Dunedin, New Zealand, 1996

B. Research Experience

Assistant Project Scientist, Department of Psychiatry, University of California at San Diego, San Diego, CA, 07/2005 - Present

Postdoctoral Fellow, Department of Psychiatry, University of California at San Diego, San Diego, CA, 06/2000 – 07/2005

Graduate Researcher, Department of Psychology, University of Otago, Dunedin, New Zealand, 02/1996 – 03/2000

Undergraduate Researcher, Department of Psychology, University of Otago, Dunedin, New Zealand, 02/1995 – 11/1995

C. Academic Awards and Honors

New Zealand Federation of University Woman (Otago Branch ) Travel Award, 1999

University of Otago Neural System Structure and Function Research Theme Grant, 1999

University of Otago Memory Theme Travel Grant, 1997 & 199

New Zealand Neurological Foundation Travel Grant, 1998 & 1999

Royal Society of New Zealand Science and Technology Award, 1998

Claude McCarthy Fellowship, 1997

University of Otago Postgraduate Scholarship, 1996-1998

University of Otago Award in Science, 1994

D. Research Grants

National Alliance for Research on Schizophrenia and Depression (NARSAD) Effie Beeman Young Investigator Award. $60,000. 2002-2004

Alzheimer’s Disease Research Center Pilot Project Grant (AG05131, NIA). $24,349. 2002

E. Professional Service

Neurological Foundation of New Zealand. Grant Reviewer. 2006

Reviewer of manuscripts for Behavioral Neuroscience, Brain Research, Learning and Memory, and Neurobiology of Learning and Memory.

Judge of student and postdoctoral presentations at the Annual Spring meeting of the Center for Neurobiology of Learning and Memory, Irvine, CA. 2002 & 2007

Otago University Memory Theme Graduate Student Representative. 1999

F. Societies

Society for Neuroscience, Member, 1997-Present

G. Invited Lectures

Brain Disorders and Cognition (Cognitive Science 172 Upper division class), UCSD, La Jolla, USA. “Brain disorders and Memory”, 2007

AAAS Pacific Division 87th Annual Meeting, San Diego, USA. Symposium: “Brain Structures Mediating Memory for Place, Object, and Emotion”. “The role of the Hippocampus in Recognition Memory”. 2006

Guest lecture for the Neuroscience 200C Graduate Class, UCSD, La Jolla, USA. “Learning and Memory Systems”. 2004.

NARSAD Annual Scientific Symposium, New York, USA. “Spatial memory, recognition memory and the hippocampus”. 2003.

Department of Physiology, SUNY, Brooklyn, USA. “The functional role of the avian hippocampus in learning and memory”. 1999.

School of Psychology, Cardiff University, Wales. “The functional role of the avian hippocampus in learning and memory” 1999.

H. Book Chapters

Broadbent, N.J., Clark, R.E., Zola, S., & Squire, L.R. (2002). The medial temporal lobe and memory. In L.R.Squire & D. Schacter (Eds.), The Neuropsychology of Memory, 3rd edition. New York: Guilford Publications, Inc.

I. Select Conference Presentations

Broadbent. N., & Colombo, M. (1997, October). “Visual discrimination and negative patterning performance following bilateral ablation to the pigeon hippocampus and area parahippocampalis”. Poster presented at the Society for Neuroscience Annual Conference, New Orleans, USA.

Broadbent, N. (1998, August). “The effects of hippocampal ablation on visual, spatial, and configural discrimination in pigeons”. Paper presented at the 16th International Australasian Winter conference on Brain Research, Queenstown, New Zealand.

Broadbent, N. (1999, August). “The role of the avian hippocampus in autoshaping, timing and spatial discrimination”. Paper presented at the 17th International Australasian Winter conference on Brain Research, Queenstown, New Zealand.

Broadbent, N., Taylor, C., & Colombo, M. (1999, October). “The avian hippocampus and the processing of temporal, contextual, visual and spatial information”. Poster presented at the Society for Neuroscience Annual Conference, Miami, USA.

Colombo, M., & Broadbent, N. (1999, October). “A comparison of the effects of hippocampal lesions in pigeons and monkeys: Evidence for functional homology?” Poster presented at the Society for Neuroscience Annual Conference, Miami, USA.

Broadbent, N.J., Clark, R.E., Zola, S., & Squire, L.R. (2001, November). “Visual paired-comparison and spatial water maze performance following dorsal or ventral hippocampal lesions in the rat”. Poster presented at the Society for Neuroscience Annual Conference, San Diego, USA.

Broadbent, N.J., Clark, R.E., & Squire, L.R. (2003, November). “Small hippocampal lesions impair spatial memory whereas large hippocampal lesions are required to impair novel object recognition”. Poster presented at the Society for Neuroscience Annual Conference, New Orleans, USA.

Clark, R.E., Broadbent, N.J., & Squire, L.R. (2003, November). “An examination of remote spatial memory with three spatial tasks following complete hippocampal lesions in rats”. Poster presented at the Society for Neuroscience Annual Conference, New Orleans, USA.

Broadbent, N.J., Squire, L.R., & Clark, R.E. (2004, November). “Impaired spatial memory retention following hippocampal lesion is not attenuated by early training or corticosterone inhibition”. Poster presented at the Society for Neuroscience Annual Conference, San Diego, USA.

Broadbent, N.J., Squire, L.R., & Clark, R.E. (2005, November). “Infusion of lidocaine into the rat hippocampus impairs recent and remote spatial memory.” Abstract accepted for the Society for Neuroscience Annual Conference, Washington, USA.

Broadbent, N.J., Squire, L.R., & Clark, R.E. (2006, June). “The role of the Hippocampus in Recognition Memory”. Paper presented at the AAAS Pacific Division 87th Annual Meeting, San Diego, USA.

Clark, R.E. & Broadbent, N.J. (2006, June). “The role of the Hippocampus in Recognition Memory”. Paper presented at the AAAS Pacific Division 87th Annual Meeting, San Diego, USA.

Broadbent, N.J., Squire, L.R., & Clark, R.E. (2006, October). “The role of the rodent caudate nucleus and hippocampus in discrimination learning and retention”. Poster presented at the Society for Neuroscience Annual Conference, Atlanta, USA.

Clark, R.E., Broadbent, N.J., & Squire, L.R. (2006, October). “Impaired water maze performance following hippocampal damage involves more than loss of spatial information”. Poster presented at the Society for Neuroscience Annual Conference, Atlanta, USA.

Clark, R.E., Broadbent, N.J., Gaskin, S., & Squire, L.R. (2007, October). “Reversible lesions of the rat hippocampus for seven days beginning immediately after training reversibly impairs spatial memory in the watermaze”. Poster presented at the Society for Neuroscience Annual Conference, San Diego, USA.

Broadbent, N.J., Gaskin, S., Squire, L.R., & Clark, R.E. (2007, October). “Large hippocampal lesions produce both anterograde and retrograde amnesia for novel object recognition in rats”. Poster presented at the Society for Neuroscience Annual Conference, San Diego, USA.

Contact Info

Phone

(858) 642-1853

Fax

(858) 552-7457

E-mail

nbroadbent at ucsd dot edu

Location

Room 340

Stein Clinical Research Building

University of California, San Diego

Regular Mail

Veterans Affairs Medical Center

116A 3350 La Jolla Village Dr.

San Diego, CA 92161-2002

Overnight Mail

University of California, San Diego

340 Stein Clinical Research Building

La Jolla, CA 92093