1. Drug discrimination by humans compared to nonhumans: current status and future directions

   • Jonathan B. Kamien
   • Warren K. Bickel
   • Brandi J. Smith

   Review Pages: 259 - 270

2. Effectiveness of nicotine patch and nicotine gum as individual versus combined treatments for tobacco withdrawal symptoms

   • K. O. Fagerström
   • N. G. Schneider
   • E. Lunell

   Original Investigations Pages: 271 - 277

3. Assessment of tardive dyskinesia by means of digital image processing

   • Wagner F. Gattaz
   • Christian Büchel

   Original Investigations Pages: 278 - 284

4. Acute behavioral and cardiac effects of cocaine and alcohol combinations in humans

   • Stephen T. Higgins
   • Craig R. Rush
   • Mark A. Capeless

   Original Investigations Pages: 285 - 294

5. Dose-dependent effects of intravenous alprazolam on neuroendocrine, biochemical, cardiovascular, and behavioral parameters in humans

   • Ossama T. Osman
   • John K. Hsiao
   • William Z. Potter

   Original Investigations Pages: 295 - 300

6. Are patterns of benzodiazepine use predictable?

   • Christian Barnas
   • Alexandra B. Whitworth
   • W. Wolfgang Fleischhacker

   Original Investigations Pages: 301 - 305

7. Subjective, behavioral and physiological responses to intravenous meperidine in healthy volunteers

   • James P. Zacny
   • J. Lance Lichtor
   • Beth Glosten

   Original Investigations Pages: 306 - 314

8. Discriminative stimulus effects of ω (BZ) receptor ligands: correlation with in vivo inhibition of [³H]-flumazenil binding in different regions of the rat central nervous system

   • D. J. Sanger
   • J. Benavides

   Original Investigations Pages: 315 - 322

9. Differences in fear motivated behaviors among inbred mouse strains

   • Ramon Trullas
   • Phil Skolnick

   Original Investigations Pages: 323 - 331

10. Development and expression of sensitization to cocaine's reinforcing properties: role of NMDA receptors

    • Susan Schenk
    • Albert Valadez
    • Brian A. Horger

    Original Investigations Pages: 332 - 338

11. The effects of haloperidol and clozapine on the disruption of sensorimotor gating induced by the noncompetitive glutamate antagonist MK-801

    • Diane C. Hoffman
    • Hilary Donovan
    • James V. Cassella

    Original Investigations Pages: 339 - 344

12. Norbinaltorphimine blocks the feeding but not the reinforcing effect of lateral hypothalamic electrical stimulation

    • Kenneth D. Carr
    • Vassiliki Papadouka
    • Toni D. Wolinsky

    Original Investigations Pages: 345 - 350

13. Altered spontaneous behavior and sensitivity to apomorphine in rats following pretreatment with S(+)-aporphines or fluphenazine

    • Alexander Campbell
    • Ross J. Baldessarini
    • John L. Neumeyer

    Original Investigations Pages: 351 - 358

14. Addition of lithium to haloperidol in non-affective, antipsychotic non-responsive schizophrenia: a double blind, placebo controlled, parallel design clinical trial

    • William H. Wilson

    Original Investigations Pages: 359 - 366

15. Morphine attenuates ultrasonic vocalization during agonistic encounters in adult male rats

    • J. A. Vivian
    • K. A. Miczek

    Original Investigations Pages: 367 - 375

16. Influence of histamine depletion on learning and memory recollection in rats

    • Chiaki Kamei
    • Yasushi Okumura
    • Kenji Tasaka

    Original Investigations Pages: 376 - 382

17. Adenosine A₂ receptor regulation of apomorphine-induced turning in rats with unilateral striatal dopamine denervation

    • Sandra V. Vellucci
    • D. J. S. Sirinathsinghji
    • P. J. Richardson

    Original Investigations Pages: 383 - 388

18. Erratum

    Erratum Pages: 389 - 390