While studying for a Bachelor’s degree at the UC Berkeley’s Psychology department, I became fascinated with consciousness, behavior, and the structure and function of the brain. I was particularly influenced by my frequent conversations with Gunther Stent, from whom I learned to embed my scientific work on a theoretical and philosophical framework.

While working for a Ph.D. at UCSD’s neuroscience department, I focused on the mechanisms by which nerve cells communicate to process sensory information and generate behavior and cognition. I contributed to document the complexity of synaptic communication and how it is modulated by environmental factors (circadian changes) and exogenous chemicals.

I demonstrated that enkephalin, an opiate peptide, was present in lobster photoreceptors, indicating an early evolutionary emergence and a wide nervous system distribution, not confined to “pain pathways” of vertebrates. My findings were published as the cover article of a special neuroscience issue of “Nature” in October 1981, distributed at that year’s Society for Neuroscience meeting.

My Ph.D. thesis work demonstrated that the photoreceptors of the horseshoe crab (limulus), an evolutionary relic, are regulated by substance P, released from nerve fibers originating in its brain. They modulate photosensitivity following a circadian cycle. I established the cellular mechanisms and traced the fibers to a central clusters of nerve cells involved in regulation of neural activity.

While finishing my graduate work, I organized a series of lectures at UCSD, in collaboration with Clifford Grobstein, covering the evolution of the universe, life and  humanity. Participants included Jonas Salk, Margaret Burbridge, William Schopf and Nobel laureates Hannes Alfven and Stanley Miller.

As a post-doctoral fellow with Floyd Bloom at the Salk Institute, I focused on examining neurotransmitter interactions. I demonstrated that somatostatin, an inhibitory transmitter, in the presence of acetylcholine, an excitatory one, would instead potentiate the excitatory response. I advocated the view that synaptic communication is not a simple algebraic summation. It has a rich complex grammar emerging from the temporal and spatial convergence of multiple presynaptic input, and the molecular events they trigger at the postsynaptic membrane.

While at the Salk Institute, I engaged in frequent conversations with Francis Crick on the subject of consciousness. Having become interested on how the pattern of specific synaptic connections are formed during development, Crick encouraged me to work with Sydney Brenner at the MRC’s Laboratory of Molecular Biology in Cambridge. I worked in Brenner’s group for 3 years, under the guidance of John Sulston.

In 1989, I set up a laboratory of Cell and Molecular Biology at the UCLA Brain Research Institute and taught at the Neurobiology Department of the UCLA School of Medicine. My research focused on using C. elegans to study the development of the nervous system. I found a number of mutants with disrupted synaptic connections and worked on establishing the role of the genes impacted, on the development of the nervous system.

While at UCLA, I participated in William Schopf’s weekly Wednesday evening dinner meetings at the Center for the Study of Evolution and Origins of Life. The small group met to share information on that subject and often had notable guests. I also met frequently with Jonas Salk at his home in La Jolla, to discuss our common interests on the evolution and future of humanity, until mid-1993.

During the 1990’s, while working at UCLA, I participated in public discussions on environmental and public health policy, through the news media and providing expert testimony before various legislative and policy bodies.

Highlights of scientific publications

For a more comprehensive list of scientific publications (1981-1993), click here.


Consciousness is the most remarkable natural phenomenon in the observable universe.
Consciousness allows living organisms to generate complex adaptive, predictive and proactive behavior and to transform their surrounding environment.
The communication of the products of conscious experience over time and space, through language and writing, is at the root of our shared reservoir of knowledge and the emergence of human civilization and science.
Understanding consciousness requires examining its emergence in the context of cosmic evolution: the unfolding of the tapestry of interactions between energy and matter, the emergence and evolution of life on earth, the rise of multicellular organisms and the role and properties of nerve cells and nervous systems.