Research

I am electrophysiologist and behavioural neuroscientist motivated to work toward a deeper understanding of how the brain's cells are born, grow, connect and organise themselves into efficient functional circuits. Communication between neurons is not constant; rather, cells can change their connectivity and communication, a phenomenon known as "plasticity". It is thought that the ability of neurons to rearrange their connections is enables the brain to grow, adapt to experience and encode long-term memories. An extensive amount of study is being done to determine the elements that either encourage or restrict neural changes (and hence memory encoding). Understanding brain principles of motivation, learning and memory, particularly in drug addiction and neurodegenerative disease, has long been a focus of my research. Currently, we are using animal model of chronic cerebral ischemia and investigating its behaviour, particularly regarding cognition, brain activity, neural circuit and neurotransmitter systems. The discovery of therapeutic drugs that can interfere with the hemodynamic and molecular effects of the disease, along with an understanding of the pathophysiology of the brain, have raised high hopes for the effective treatment of stroke and dementia. This animal model has been used as a benchmark for Alzheimer's illness. Our goal is to identify any prospective plants that may have memory-enhancing and neuroprotective characteristics to be developed as "Smart Drug”. 

Current Research Projects:

• Role of dopamine and its reflection in spectral frequencies of EEG in freely moving addictive rats
• Behavioural research in addiction
• Effects of psychoactive drugs on changes in spontaneous electroencephalographic (EEG) and behavioral activities in addictive animal models
• Neural mechanism of mitragynine (a major indole alkaloid of Mitragyna speciosa) rewarding properties and neurochemical events in several discrete brain areas: potential treatment of opiate addiction
• Evaluation of addiction severity and withdrawal effect in mitragynine treated rats
• Neuroplasticity and role of cholinergic system in cognitive behaviour
• Brain activity (EEG) and synaptic plasticity in chronic cerebral ischemia model
• Neuroprotective effects of standardized Clitorea ternatea root extract for the treatment of memory disorders and improving cognitive behaviour in chronic cerebral ischemia model
• Evaluations of neuroprotective activity of standardized ethanolic Orthosiphon stamineus extract to ameliorate cognitive alterations in Alzheimer's disease

People

Current PhD students (as main supervisor)

• Mohamad Azmeer Effendy Md Salim
• Rahimah Hassan
• Nurul Aqmar Mohamad Nor Hazalin
• Thenmoly A/P K Damodaran
• Nurul Hasnida Mohammad Yusof

Current MSc student (as main supervisor)

• Tiang Ning

Publications

SELECTED PUBLICATIONS (FROM 2010)

1. Damodaran, T., Tan, B.W.L., Liao, P., Ramanathan, S., Keat, L.G., Hassan, Z. (2018) Clitoria ternatea L. root extract ameliorated the cognitive and hippocampal long-term potentiation deficits induced by chronic cerebral hypoperfusion in the rat. J Ethnopharmacol., 224, 381-390.
2. Yusoff, N.H.M., Mansor, S.M., Müller, C.P., Hassan, Z. (2018) Baclofen blocks the acquisition and expression of mitragynine-induced conditioned place preference in rats. Behav Brain Res., 345, 65.
3. Hassan, Z., Bosch, O.G., Singh, D., Narayanan, S., Kasinather, B.V., Seifritz, E., Kornhuber, J., Quednow, B.B., Müller, C.P. (2017) Novel Psychoactive Substances-Recent Progress on Neuropharmacological Mechanisms of Action for Selected Drugs. Front Psychiatry, 8, 152.
4. Yusoff, N.H.M., Mansor, S.M., Müller, C.P., Hassan, Z. (2017) Opioid receptors mediate the acquisition, but not the expression of mitragynine-induced conditioned place preference in rats. Behav Brain Res., 332, 1-6.
5. Müller, C.P., Hassan, Z. (2016) The evaluation of new psychoactive drugs. Brain Res Bull., 126 (Pt 1), 1-2.
6. Suhaimi, F.W., Yusoff, N.H., Hassan, R., Mansor, S.M., Navaratnam, V., Müller, C.P., Hassan, Z.  (2016) Neurobiology of Kratom and its main alkaloid mitragynine. Brain Res Bull., 126 (Pt 1), 29-40.
7. Yusoff, N.H., Suhaimi, F.W., Vadivelu, R.K. , Hassan, Z., Rümler, A., Rotter, A., Amato, D., Dringenberg, H.C., Mansor, S.M., Navaratnam, V., Müller, C.P. (2016). Abuse potential and adverse cognitive effects of mitragynine (kratom). Addiction Biology, 21 (1), 98-110.
8. Mustaffa, F., Hassan, Z., Asmawi, M.Z. (2016). Cinnamomum iners leaves as an alternative therapy for diabetes. Asian Journal of Biochemistry, 11 (1), 44-52.
9. Mustaffa, F., Hassan, Z., Asmawi, M.Z. (2016). Antioxidant activity of Cinnamomum iners leaves standardized extract. Asian Journal of Biochemistry, 11 (2), 90-96.
10. Harun, N., Hassan, Z., Navaratnam, V., Mansor, S.M., Shoaib, M. (2015) Discriminative stimulus properties of mitragynine (Kratom) in rats. Psychopharmacology (Berl), 232 (13), 2227-2238.
11. Harun, N., Hassan, Z., Navaratnam, V., Mansor, S.M., Shoaib, M. (2014) Discriminative stimulus properties of mitragynine, an alkaloid derived from leaves Mitragyna speciosa (Kratom). Journal of Psychopharmacology, 28 (8), A88.
12. Mustaffa, F., Hassan, Z., Yusof, N.A., Razak, K.N.A., Asmawi, M.Z. (2014) Bioassay-guided antidiabetic mechanisms of Cinnamomum iners leaves extract. World Journal of Pharmaceutical Research, 3 (6), 1924-1935.
13. Damodaran, T., Hassan, Z., Navaratnam, V., Muzaimi, M., Ng, G., Müller, C.P., Liao, P., Dringenberg H.C. (2014) Time course of motor and cognitive functions after chronic cerebral ischemia in rats. Behav Brain Res., 275, 252-258.
14. Kura, A.U., Cheah, P.S., Hussein, M.Z., Hassan, Z., Tengku Azmi, T.I., Hussein, N.F., Fakurazi, S. (2014) Toxicity evaluation of zinc aluminium levodopa nanocomposite via oral route in repeated dose study. Nanoscale Res Lett., 9 (1), 261.
15. Mustaffa, F., Hassan, Z., Yusof, N.A., Abdul Razak, K.N., Asmawi, M.Z.  (2014) Antidiabetic and antihyperlipidemic potential of standardized extract, fraction and subfraction of Cinnamomum iners Leaves. International Journal of Pharmacy and Pharmaceutical Sciences, 6 (5), 220-225.
16. Mustaffa, F., Hassan, Z., Yusof, N.A., Abdul Razak, K.N., Asmawi, M.Z.  (2014) Antidiabetic mechanism of standardized extract, fraction and subfraction of Cinnamomum iners leaves. Int. J. Pharm. Sci. Rev. Res., 26 (2), 209-214.
17. Manshor, N.M., Dewa, A., Asmawi, M.Z., Ismail, Z., Razali, N., Hassan, Z. (2013) Vascular reactivity concerning Orthosiphon stamineus Benth-mediated antihypertensive in aortic rings of spontaneous hypertensive rats. International Journal of Vascular Medicine, Article ID 456852.
18. Hassan, Z., Sattar, M.Z., Suhaimi, F.W., Yusoff, N.H., Abdulla, M.H., Yusof, A.P., Johns, E.J. (2013) Blunted endogenous GABA-mediated inhibition in the hypothalamic paraventricular nucleus of rats with streptozotocin-induced diabetes. Acta Neurol Belg., 113 (3), 319-325.
19. Razali, N., Dewa, A., Asmawi, M.Z., Ismail, Z., Mansor, N.M., Hassan, Z. (2013) Vascular reactivity on aortic rings of spontaneously hypertensive rats treated with methanolic and water extracts of Ficus deltoidea. J Exp Integr Med., 3 (2), 93-102.
20. Hassan, Z., Muzaimi, M., Navaratnam, V., Yusoff, N.H., Suhaimi, F.W., Vadivelu, R., Vicknasingam, B.K., Amato, D., von HÖrsten, S., Ismail, N.I., Jayabalan, N., Hazim, A.I., Mansor, S.M., Müller, C.P. (2013) From kratom to mitragynine and its derivatives: physiological and behavioral effects related to use, abuse, and addiction. Neurosci Biobehav Rev., 37 (2), 138-151.
21. Hassan, Z., Dewa, A., Asmawi, M.Z., Sattar, M.Z. (2011) Assessment of vascular reactivity at different time-course on STZ-induced diabetic rats. J Exp Integr Med., 1 (3), 175-183.
22. Hassan, Z., Yam, M.F., Ahmad, M., Yusof, A.P. (2010) Antidiabetic properties and mechanism of action of Gynura procumbens water extract in streptozotocin-induced diabetic rat. Molecules, 15 (12), 9008-9023.

Published Abstract

1. Nur Hidayah Kaz Abdul Aziz, Norhalida Hashim, Zurina Hassan (2017) Differential effects of parity, stress and fluoxetine treatment on locomotor activity and swimming behavior in rats. World Academy of Science, Engineering and Technology International Journal of Pharmacological and Pharmaceutical Sciences, 11(12), urn:dai:10.1999/1307-6892/80531.
2. Nor Fasihah Azam, Zurina Hassan, Hans C. Dringenberg (2014) The effect of permanent occlusion of common carotid arteries on electroencephalogram (EEG) in rat’s brain. Archives of Pharmacy Practice, 5 (Supplement 1), S9.
3. Hasnida, N., Yusoff, M., Hassan, Z., Visweswaran, N., Müller C.P. (2013) Simultaneous monitoring of conditioned place preference and locomotor sensitization in mitragynine-treated rats. Behavioural Pharmacology, 24 (e-Supplement Abstract of the 15th Biennial Meeting of the European behavioural Pharmacology Society, La Rochelle, September 6-9, 2013) e58, October 2013.
4. Mohammad Yusoff, N., Hassan, Z., Navaratnam, V., Müller, C.P. (2012) Effects of acute mitragynine exposure on the establishment of conditioned place preference and locomotor activity. Front. Hum. Neurosci. Conference Abstract: ACNS-2012 Australasian Cognitive Neuroscience Conference. doi: 10.3389/conf.fnhum.2012.208.00118.
5. Hassan, Z., Sofian, Z.M., Navaratnam, V. (2012) Changes in the spontaneous EEG and locomotor activity of freely moving rats in mitragynine-treated animals. Front. Hum. Neurosci. Conference Abstract: ACNS-2012 Australasian Cognitive Neuroscience Conference. doi: 10.3389/conf.fnhum.2012.208.00042.
6. Suhaimi, F., Hassan, Z., Navaratnam, V., Müller C.P. (2012) Impairment of memory formation, consolidation and retrieval of inhibitory avoidance task in acute mitragynine-treated rats. Front. Hum. Neurosci. Conference Abstract: ACNS-2012 Australasian Cognitive Neuroscience Conference. doi: 10.3389/conf.fnhum.2012.208.00176.