Kozhalmannom Subramaniasastry Krishnan (1946-2014) was an Indian scientist born in Palakkad, Kerala. Krishnan's scientific career made a slow progress, tied as it was to institutional rules and regulations. His science, on the other hand, untethered to man-made limitations, thrived on the novel methods he devised to find answers to his questions. His science was often discussed as emerging from an unending curiosity, driven by a passion for nature and the people around him, making it free of labels and devoid of silos.

Krishnan fancied the idea of being a neuroscientist at a time when it was still a new field in India. So despite his academic training in applied physics and experience at the Bhabha Atomic Research Centre (BARC), he chose to delve into bio-physics for his doctorate. He studied mammalian brains under his young mentor, P Balaram, at the Indian Institute of Science, Bangalore from 1972 to 1975. He collaborated with JF Brandts at the University of Massachusetts, Amherst, for post-doctoral work and returned to India at the invitation of Obaid Siddiqi. Krishnan was among the early recruits to work on the fruit fly Drosophila melanogaster at the Molecular Biology Unit at the Tata Institute of Fundamental Research (TIFR), Bombay in the late 1970s. In the summer of 1979, he went on an exchange program to the MRC Laboratory for Molecular Biology at Cambridge, UK, to learn how to make monoclonal antibodies. Upon returning, he set up what is considered to be among the first labs to synthesize monoclonal antibodies in India.

For over three decades, Krishnan studied D. melanogaster adopting various approaches – molecular, genetics, chemical - in an attempt to understand synaptic transmission. He examined membrane proteins, experimented with temperature-sensitive mutants, analyzed phenotypes of these mutations, studied endocytosis and looked at dynamin-dependent synaptic vesicle recycling. He is best known for his work on the anesthetic effects of halothane on D. melanogaster, which he did with Howard Nash at the Laboratory of Molecular Biology, National Institute of Health (NIH), Bethesda, Maryland in the United States from 1988 to 1990. Their work challenged the then widely accepted Meyer-Overton principle, which stated that lipid solubility determined anesthetic potency. Nash and Krishnan's work went further to find that the variation in the anesthetic property has a genetic basis. Their work found mention in the BBC documentary, Moments of Genius.

Krishnan was a tinkerer at heart. He enjoyed rigging things up and improvising along the way. He designed and fabricated several contraptions to conduct his experiments. His work with Nash was made possible by what is now famously known as the 'inebriometer' - a tall, twin, tubular device used to screen D. melanogaster mutants resistant to halothane; the ones higher up in the device are more resistant. While there did exist a device to screen fruit flies, Krishnan's ingenuity lay in reshaping this device based on a contraption he had seen in Balaram's lab at IISc. That device used long glass columns to fractionate solvents – the longer the glass column, the better the distillation.

Another of his penchants, for nomenclature, was at play when one of his other devices, called the 'sushi cooker', led to the finding that certain affected flies fell asleep for days at a stretch – leading him to term the mutation 'Kumbhakarna', after a sleeping demon in the epic, Ramayana. After years of Drosophila research, Krishnan was able to combine his love for nature with his scientific queries. His former TIFR colleague, Mani Ramaswami, introduced him to Baldomero 'Toto' Olivera. Toto's pioneering work in conotoxins i.e. cone snail toxins, piqued Krishnan's curiosity enough for him to find out how conotoxins blocked the perception of pain in animals. He sought to explore if these held pharmacological applications as medicinal pain relievers. At the turn of the century, he collaborated with Balaram to study marine animals' use of neurotoxins in predatory behaviour. Over time, the collaboration expanded from studying cone snails to marine molluscs, wasps and frogs, in what became a multi-institutional "chemo-genetic" approach to studying synaptic transmission.

These studies led to two patents in the names of Krishnan and Balaram, spurred by Krishnan's enthusiasm for marine ecology and an uncanny ability to find solutions. His colleagues and collaborators recall that when Krishnan first held a marine cone snail, he wasted no time in collecting the sample - a local barber's knife was used to pry out the snail that had receded into the shell and the venom extracted was preserved in alcohol bought at the local arrack shop.

Krishnan's passion went beyond marine life. He had an enduring interest in avi fauna, and had even considered a sabbatical from TIFR to pursue ornithology at the same time when he received an invitation from the Nash lab in Bethesda. He enjoyed going on bird-watching trips and documented birdcalls. He floated the idea and supervised the execution of documenting the birds and butterflies on TIFR's Colaba campus for the institute's 50th anniversary celebrations in 1991.

Although there is nothing to suggest that he studied birds in a scientific manner, he regularly embarked on bird-watching trips, documented birdcalls, attended ornithology conferences and was on the planning committee of the first SERB school in avian biology in 2013.

Kits to his peers and KSK to his students, Krishnan has been described as an original thinker, creative, chaotic, fire-starter, friendly, charming and persuasive. He did face personal and professional obstacles in the late 1980s, but he remained undeterred by setbacks. Some of his finest work, his peers say, came about after the setback in 1988. Krishnan himself often reminded his students to view obstacles as an opportunity for discovery. Impervious to his surroundings, he was known to walk into the laboratories of colleagues and peers, readily offering inputs and suggestions to young researchers. He was quick to make friends and his unending enthusiasm for people paved the way for collaborations that would otherwise have been unlikely.

Krishnan eschewed group affiliations. He didn't particularly care for titles, designations or memberships and didn't allow his career to be defined by such labels. He made no distinction while interacting with members from his fraternity or outside. And this ability ensured he established an instant connection irrespective of whether it was children, students or peers he was dealing with. Students, peers and fellow scientists describe him as a man whose thoughts raced so far ahead of his words so as to be incoherent. It was a challenge to keep pace with the multiple threads in his conversations and yet he wielded a wide influence. He is said to have instilled a deep spirit of scientific query in his students and colleagues. To Krishnan's foresight is also attributed the creation of inter-disciplinary ecosystems for students and academicians. He was instrumental in initiating the one-of-a-kind Master's in Wildlife programme at the National Centre for Biological Sciences (NCBS), Bangalore. And partly due to his cheerleading, the Department of Science and Technology conducts schools sponsored by the Science and Engineering Research Board (SERB) and Science and Engineering Research Council (SERC) in diverse fields like neuroscience, chronobiology, herpetology, avian biology, as well as chemical ecology.

In 2003, Krishnan was made a joint faculty member at TIFR affiliate NCBS. His tenure at TIFR was extended on three occasions from 2006 onwards. It was at around this time that NCBS evolved a policy that allowed retired faculty to continue their scientific pursuits post retirement. He relocated with his wife, Chandra, to Bangalore in 2008 and continued to work out of the NCBS campus after superannuating. He died suddenly due to a cardiac arrest on 24 May 2014.