Note 4 - Equity (Details Textual)												1 Months Ended		3 Months Ended						9 Months Ended		12 Months Ended
	Nov. 10, 2025 USD ($)	Oct. 21, 2025	Oct. 01, 2025 USD ($) shares	Aug. 15, 2025 shares	Jun. 11, 2025 USD ($)	Jan. 01, 2025 shares	Mar. 21, 2024 USD ($) $ / shares shares	Feb. 02, 2024	Jan. 01, 2024 shares	Dec. 13, 2023	Apr. 03, 2018 shares	Nov. 14, 2025 USD ($) shares	Mar. 31, 2024 USD ($) $ / shares shares	Sep. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2025 USD ($) $ / shares shares	Mar. 31, 2025 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Sep. 30, 2025 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares	Oct. 29, 2025 $ / shares shares	Oct. 24, 2025 $ / shares shares	Dec. 31, 2023 $ / shares shares	Jul. 31, 2023 $ / shares	Mar. 31, 2023 $ / shares
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares													$ 297.21	$ 499.26	$ 503.75	$ 503.75	$ 503.74	$ 361.6	$ 297.21	$ 499.26	$ 503.74	$ 503.75			$ 4,054.81
Class of Warrant or Right, Exercised During Period (in shares)														0	0		15,580	11,962
Proceeds from Issuance of Common Stock | $																				$ 10,714,593	$ 8,029,143
Derivative Liability | $														$ 243,000						$ 243,000		$ 0
Stock Issued During Period, Value, Issued for Services | $														$ 1,335	$ 366,702	$ 4,505	$ 9,650	$ 14,850	$ 180,720
Stock Issued During Period, Shares, Reverse Stock Splits (in shares)																					1,294
Preferred Stock, Shares Authorized (in shares)														10,000,000						10,000,000		10,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001						$ 0.001		$ 0.001
Preferred Stock, Shares Outstanding (in shares)														0						0		0
Common Stock, Shares Authorized (in shares)														200,000,000						200,000,000		200,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares														$ 0.001						$ 0.001		$ 0.001
Common Stock, Shares, Outstanding (in shares)														1,004,247						1,004,247		217,234
Class of Warrant or Right, Issued in Period (in shares)																0			64,124
Warrants or Rights, Cancelled During Period (in shares)														25			0
Share-Based Payment Arrangement, Expense | $														$ 19,553			$ 420,226			$ 663,243	$ 3,034,966
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)													5,741	5,705	5,705	5,705	5,709	5,718	5,741	5,705	5,709	5,706			5,750
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)																				10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share) | $ / shares													$ 6,061.27	$ 6,081.93	$ 6,081.93	$ 6,081.93	$ 6,079.87	$ 6,074.65	$ 6,061.27	$ 6,081.93	$ 6,079.87	$ 6,081.61			$ 6,054.32
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)														0			0			0	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period (in shares)														0	0	1	9	23	9	1	41
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price (in dollars per share) | $ / shares														$ 0	$ 0	$ 4,280	$ 2,766.67	$ 2,734.78	$ 1,620	$ 4,280	$ 2,497.07
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)																				4 years 4 months 13 days		5 years 1 month 9 days
Class of Warrant or Right, Outstanding (in shares)													67,176	39,608	39,633	39,633	39,634	55,214	67,176	39,608	39,634	39,633			3,052
Common Stock [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)														100	23,837	100	100	100	728
Stock Issued During Period, Value, Issued for Services | $														$ 0	$ 24	$ 0	$ 0	$ 0	$ 1
Stock Issued During Period, Shares, Reverse Stock Splits (in shares)																			1,294
The 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)											2,080
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)											1,314
Share Based Compensation Arrangement By Share Based Payment Award, Percentage Applied on Outstanding Shares of Common Stock For Automatically Increase on Each Year											5.00%
Amended 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares)				130,000		10,861			1,486
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)														144,588						144,588
The 2018 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)											105
Share Based Compensation Arrangement By Share Based Payment Award, Percentage Applied on Outstanding Shares of Common Stock For Automatically Increase on Each Year											2.00%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)														509						509
Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares)																				1,785	633
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested | $																				$ 21,922	$ 96,524
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation (in shares)																				328	202
Restricted Stock Units (RSUs) [Member] | Share-Based Payment Arrangement, Employee [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures (in shares)														240			1			246	7
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures (in shares)																				1,600
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense | $														$ 20,000.00			$ 400,000			$ 700,000	$ 3,000,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $														60,000.00			600,000			$ 60,000.00	$ 600,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)																				1 year 4 months 20 days	6 months 29 days
Share-Based Payment Arrangement, Option [Member] | Research and Development Expense [Member]
Share-Based Payment Arrangement, Expense | $														10,000.00			200,000			$ 100,000	$ 500,000
Share-Based Payment Arrangement, Option [Member] | General and Administrative Expense [Member]
Share-Based Payment Arrangement, Expense | $														$ 10,000.00			$ 200,000			$ 600,000	$ 2,500,000
Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)														0						0
Scientific Advisory Board Chairman [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)														100			100			300	203
Stock Issued During Period, Value, Issued for Services | $														$ 1,335			$ 9,650			$ 6,990	$ 25,904
Service Providers [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)																					725
Stock Issued During Period, Value, Issued for Services | $																					$ 179,550
Board Members [Member] | Common Stock [Member]
Shares, Issued (in shares)														1,790						1,790
Executives, Employees, and Non-employee Directors [Member] | Common Stock [Member]
Shares, Issued (in shares)																	636				636
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Month)																				48 months
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share) | $ / shares														$ 19,600						$ 19,600
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares																				$ 15,860
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Month)																				12 months
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share) | $ / shares														900						$ 900
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares																				631
March 2024 Pre-Funded Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							27,543
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares							$ 0.005							$ 7,620			$ 0.005			$ 7,620	$ 0.005
Class of Warrant or Right, Exercised During Period (in shares)																						27,543
Stock Issued During Period, Shares, Issued Due to Exercise of Warrants (in shares)																	15,580				27,543
Class of Warrant or Right, Issued in Period (in shares)														0			0			0	27,543
Warrants or Rights, Cancelled During Period (in shares)														25						25
Share-Based Payment Arrangement, Expense | $														$ 0						$ 0
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $														$ 300,000						$ 300,000
March 2024 Common Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							30,843
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares							$ 204.5										$ 204.5				$ 204.5
Warrants and Rights Outstanding, Term (Year)							5 years
March 2024 Common Warrants [Member] | Maximum [Member]
Class of Warrant or Right, Issued in Period (in shares)																					30,843
March 2024 Pre-Funded Warrant and Common Warrant [Member]
Class of Warrant or Right, Combined Purchase Price | $							$ 210.75
Amended Registered Direct Offering [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares							$ 204.5										$ 204.5				$ 204.5					$ 1,770	$ 2,200
Warrants and Rights Outstanding, Term (Year)							5 years										5 years				5 years
Class of Warrant or Right, Amendment Price Per Warrant (in dollars per share) | $ / shares							$ 6.25
Class of Warrant or Right, Issued in Period (in shares)																					3,885
Amended Registered Direct Offering [Member] | Maximum [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							3,886
Placement Agent Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares																	$ 260.44				$ 260.44
Stock Issued During Period, Shares, Issued Due to Exercise of Warrants (in shares)																					11,963
Class of Warrant or Right, Issued in Period (in shares)																					1,851
Vesting of Warrants For Service Provider [Member]
Share-Based Payment Arrangement, Expense | $																	$ 2,280				$ 18,039
Outstanding Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)														39,608						39,608
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares														$ 499.26						$ 499.26
Warrants and Rights Outstanding, Term (Year)														5 years						5 years
Outstanding Warrants [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares														$ 14,440						$ 14,440
Warrants or Rights, Fair Value Per Share (in dollars per share) | $ / shares														9,250.2						9,250.2
Outstanding Warrants [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares														204.5						204.5
Warrants or Rights, Fair Value Per Share (in dollars per share) | $ / shares														$ 60.67						$ 60.67
Performance-based Warrant [Member]
Class of Warrant or Right, Outstanding (in shares)														1						1
Warrant, Nonvested Award, Cost Not yet Recognized, Amount | $														$ 300,000						$ 300,000
Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)							3,300
Equity Offering, Combined Purchase Price (in dollars per share) | $ / shares							$ 210.75
Proceeds from Issuance or Sale of Equity, Total | $													$ 5.8
The 2023 ATM Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)														0			42,990			338,811	46,370
Brokerage Commissions, Percentage of Gross Proceeds										3.00%
Proceeds from Issuance of Common Stock | $																	$ 1,215,105			$ 6,895,947	$ 2,117,752
The 2025 ELOC Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)														341,224						422,380
Proceeds from Issuance of Common Stock | $														$ 2,943,745						$ 3,818,631
Equity Issuance, Maximum Amount, Available for Issuance | $					$ 12,500,000
Derivative Liability | $														$ 243,000						$ 243,000
Stock Issued During Period, Shares, Issued for Services (in shares)														341,224
The 2025 ELOC Facility [Member] | Commitment Shares [Member]
Stock Issued During Period, Shares, New Issues (in shares)																				23,737
Proceeds from Issuance of Common Stock | $																				$ 365,550
March 2024 Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)																					3,300
Proceeds from Issuance of Common Stock | $																					$ 5,800,000
Subsequent Event [Member] | Scientific Advisory Board Chairman [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)			100
Subsequent Event [Member] | Placement Agent Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)																							22,667	14,617
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares																							$ 11.25	$ 14.0125
Warrants and Rights Outstanding, Term (Year)																							24 months	24 months
Subsequent Event [Member] | The 2023 ATM Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)												242,537
Proceeds from Issuance of Common Stock | $												$ 1,006,740
Equity Issuance, Maximum Amount, Available for Issuance | $	$ 11,495,000
Subsequent Event [Member] | The 2025 ELOC Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)			326,750
Proceeds from Issuance of Common Stock | $			$ 1,434,139
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio								40
Reverse Stock Split [Member] | Subsequent Event [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio		50